#MDCAT Physics Unit#1 Force & Motion Lecture#2

0:00 [music] Now the last one was the displacement time graph I will revise it a little for you initially. get Give displacement time What information does the graph give us about it What we know about displacement If we calculate the slope of the time graph

0:46 If we do this then this slope gives us the result of velocity gives if so The slope that we have is displacement The slope of the time graph is equal to How do we get velocity now? things happen, we've talked about it, I Draw a common graph only up to the extent of revision and inside that graph we'll see that How did all these cases that we had come up with come from So let's have this graph Along Y axis inside the graph Displacement is along X axis time The first reason I draw is white So I'll name this region AB

1:34 The graph of is a straight line but inclined is above a certain angle then the graph Again it is a straight line but parallel to The x axis is what I'll call B. C After this the graph is the curve now this curve I mean you know what this is this increasing the slope is, after this this point d comes, its after that i draw a graph what is this graph is showing decreasing slope to now Point e after that come back down then I draw a straight line in the graph Two cases after two points A now point F I'm going to draw here. I'm going to draw a curve. from f tos and lastly in dr I do it from g to

2:20 h these are all the graphs that we saw in the last table which we discussed in the form of a Mention it at the same place now Now we need to look inside these graphs What is the velocity above each point of the and what is acceleration I start from A to B if we go to A Talking about A to B, what is the A to B graph showing that displacement is Increasing Uniform Graph Straight Line and the angle is our constant mean slope is constant then a to b we have What will the graph represent? If I write here A to B then that show will do uniform velocity and if the velocity is uniform then We know we have the power of acceleration Value Zero so after a to b we go b to c

3:08 if we look at b to c then b to c graph is a straight line parallel to the x axis its This means that from b to c we have overall The value of displacement is The value of displacement is constant constant means rate of change of displacement row it means body here At rest our velocity is zero and if If the velocity is given then the value of acceleration is also given Zero hogi next let's move ahead to point c to d Now C2D see one thing that if we every draw a tange eight above the point So the angle of that angle increases in the start if you look at the angle then angle is small and later angle increases did it and we know that the slope which would have been yes that is directly proportional to no Theta Your Theta will increase from row to row

3:55 90 We also have the value of that slope what will be more So here if we talk about C2D If we do it then what can we do towards C2D will say that we have increasing slope Increasing the slope would mean that The velocity is increasing but the graph If it is not a straight line then what will it say The graph is of increasing velocity but The variable is increasing but the variable Velocity is now one more thing we need to take from here I found out about the acceleration now the acceleration which is that is non zero and if the velocity increases If you are doing this then what will be the acceleration If it is positive then it is a sign of positive acceleration The graph is let's move forward from d to e now d If we go from d to e then from d to e

4:43 If you draw a tange on every point So now we have the angle theta is decreasing means slope if it is decreasing then what are we we will say that we have velocity is variable but if the slope decreases If it is decreasing then it is decreasing velocity Graph Its graph will be decreasing velocity so what shall we say here would say that acceleration is non zero but negative now next i would like you guys to Answer e to f Now mention what is the answer velocity and acceleration will be same like f twos and g two h next three you guys I have to answer it till now, I have told you Now whatever answer you people give, that will be the answer e

5:30 Apart from f and e, you will answer ag and Apart from this I will answer g A ka ji now let's see what we have Are people's answers correct or incorrect If we go from e to f then the graph is straight line means it is uniform velocity if it represents then what is the difference between A to b and e to f in e to b a to b and e to The difference in f is that from a to b we have The slope of this point is positive Above velocity is positive but we are going from e to f so if we talk about the slope that we have here that's negative because if we take the angle theta If we look at it then it is in the fourth quadrant The line is coming inside, it means that The velocity here will be negative

6:16 Now let's talk about acceleration Here f2g is equal to zero f2g again see the slope now here if you see the slope So let's see, our angle in the beginning is It is close to K which means the slope is higher and Slowly the angle approaches zero the angle is decreasing it means that The graph of decreasing velocity will be is the decreasing velocity and the graph curve is Because of this, what will we say to this Variables now the acceleration here will be non zero and if it is decreasing then its So what will be the sign of acceleration here? It will come negative. Now here also if we see what's the difference kiddy to e and f what is the difference in 2G so we have The difference will be that to e we have the slope

7:03 is positive velocity is positive but f2g What is our slope negative so velocity what will happen will it be negative and last g to a So initially our angle is zero The angle of the angle is gradually decreasing what does it mean it is increasing is negative and it is an increasing variable Velocity what would you say that acceleration is non zero and if it is increasing then this What will happen, if it is positive then we have revised it I completed all the last topic Let me tell you one more thing about the cases here that the area of ​​this graph gives us any information if this total area is calculated then it does not give If you want to do this then you can do it with any physical quantity not equal to

7:49 Now let's move on to our next topic on the side which is today's topic and in a way The entire concept that we have discussed will also be revised We will implement what we just read But now we will see the graph and the velocity Graph versus time which will be the graph of velocity versus time It gives us two informations: a graph from the slope of and also the area of ​​the graph from and area remember the area under the Graph Towards Time What information does the access slope give us? The slope gives us information What does acceleration mean if velocity If there is a time graph then velocity in time graph If we find the value of theta then

8:35 Many times our acceleration will be equal to Question displacement time or velocity The times are such that the graph which is made Let's say if I say it's displacement time is same and there are two different Graphs are one graph is inclined 30 degrees and a graph is inclined at 45 On degree it is said that tell these What will be the ratio of velocities in To find the ratio of velocities Simply what you do is find the ratio of theta If we find it then we will find the velocity ratio If it is calculated then in this question There is nothing difficult if I am able to I tell me I need to calculate over v b So simply I have the angle of A which is 30 and Remember, divide it with the x axis I will do it with 45 so what is 45 and and not 30 1 o under √3 so 1 o under √3 its

9:22 The answer will be more i.e. the velocity of B it is more than this thing It also applies here in case of Acceleration is the second thing, area under the graph About area in velocity time graph I discussed two things that if Simply we calculate the area If you cannot do algebra summing then remember this But the area that will come is based on the total distance will come equal and if we see the area here find in algebraic form that which Our reference axis is above that so above The area below will take the positive If you take negative then when you do sum then algebraic sum area distance will not work If the displacement is equal then this thing Remember here that velocity is time Area in a graph is simple distance

10:08 And if we take algebra, then it equal to displacement comes now we Let's discuss its cases same method that we did in the last topic one Buy one we have different possibilities discus them The first column of the graph will be where We will draw the graph in the second column. What information does velocity t give? after that we'll talk about slope And after the slope we will see that the graph what do we know about acceleration Information was being received if yes then first Possibility velocity along y time along x The graph is a straight line parallel to the x axis What information does this graph give us?

10:55 The overall velocity that we have is is constant i.e. change in velocity is equal to zero slope so what is the angle here zero no 0 0 that mean slope is zero and slope if zero so what is this telling us The value of acceleration is also zero here You can also write uniform instead of constant is the graph of uniform velocity So write the constant here and you can use it as what should i write in uniform Write this is the first case and if you have written here If you want to calculate area then calculate area You guys will have a very simple method to do it what will you do under the curve of this graph Calculate area towards time axis So what shape is this? This is a rectangle So if you have area required here

11:41 that if you calculate the distance here If you want to do it then to calculate the distance Area will be the product of base and height move on to the next graph The next graph is also a straight line But now this is a straight line and this is inclined There is a certain angle above the top with Respect to each other's time with now any if this angle this angle The uniform is staying, this means now we What shall we say about Velocity? would say velocity is increasing Uniform Uniform Velocity Increase If the velocity is increasing uniformly then If so, what will you say about the slope? that the slope b is uniform means the angle change If it is not happening then is the slope uniform?

12:27 It is positive or negative, our angle is 90 what is the degree and angle if 90 If it is less than degrees then what is the slope positive and the answer slope that you will remember Keep the same answer for acceleration as well Slope if uniform and positive what about acceleration that this We also have uniform acceleration is the acceleration and for uniform acceleration Apart from this, know if it is positive or negative It turned out that the velocity was increasing The slope is positive, which means it is positive Graph of Uniform Acceleration As far as the area is concerned, we will take this line If you calculate the area below then which one is this C shape is triangle so here the distance To calculate, we use the triangle take the area half base into height then

13:14 Let me repeat this towards time access You calculated the area on the time axis Do not find the velocity axis do next Moving on to the Possibility Third Graph Let's draw another velocity-time graph but the graph we have now is straight line but now it's inclined This graph is not upward but downward now what is the show doing this show is doing that The value of velocity is decreasing But the uniform is decreasing but if we talk about the angle This angle of ours is greater than 90 means the slope is not positive If it is negative then the slope is uniform But what is the difference between second and third The difference is that this is a positive slope and

14:00 This is a negative slope, which means that If there is a graph of uniform return then many times Our MCQs are such that discussion and The following graph represents uniform Returns if velocity increases uniformly If it is there then we will call it change in Velocity is also uniform, that's why Uniform acceleration is if velocity is Increasing uniforms that mean overall change in velocity is uniform now acceleration what will we say here Graph of Negative Uniform Acceleration You can call negative uniform acceleration a And you can also name this uniform This is the graph of Rita Dation, now let's look at the distance

14:48 On the other hand if you want to calculate the distance is simply the area under this triangle Find out what the area will be in half base Your distance will be calculated based on your height This is the possibilities of a straight line Whether inclined or parallel to x Axis now fourth graph now we talk about curve We will do it as we talked about in displacement By the way, here also the graph The fourth graph is velocity time and the fifth I'll draw them both together so that The comparison comes to us Well, this is our fourth graph, you can understand it from this it seems to us that the slope is increasing And the fith graph is this and it can be known from this it seems that the slope is decreasing but remember in both of them

15:33 What is Velocity doing overall if time Velocity is increasing in both It is increasing but in the fourth graph velocity we have the variable we have There is a variable in the fifth as well, what is the difference Fourth graph of slope i.e. acceleration inside what would we say we would say that Velocity is increasing non-uniform This means that what we have acceleration is what is that variable Acceleration is not uniform and the slope what is also a variable what is also acceleration Now let's talk about positive and negative variables If we do this then the velocity is increasing If velocity is increasing it means this will be the acceleration we have

16:21 what will she be she will be positive what about Slope Is the slope increasing or decreasing? so if we look at the slope then we have the starting point The angle in is close to zero and Slowly slowly it is getting closer to 90 This means theta is increasing and theta If you see, theta is less than 90 This means the slope is positive only then the sign here what came, it came positive but what about the slope If there is an increase then this is a slow variable But it is increasing, it means here there is a There is also information that acceleration is positive variable and in addition another I got the information, what is acceleration Increasing Acceleration Ye Increasing Positive and Variable Acceleration The graph of As far as area is concerned then this graph will be

17:09 if it is not a straight line then here we have the parts will have to be divided and the total The area will come to us at a distance If you look at the fifth graph, it will be equal Inside the fifth graph we initially have which is the angle and the subsequent angle in it What is the difference initially the angle is 90 It is close and slowly moving towards zero going close, what does it mean here The angle is decreasing but from 90 What is laser so what do we know about it we will say that velocity is Increasing But None What is uniform slope If the slope is variable but now the slope is not increasing What is the slope, it is decreasing what will you say about acceleration acceleration is variable velocity is increasing

17:54 if acceleration is positive slope what do you do There is a decrease, it means extension here also what are you doing, if you are decreasing then This is information that comes from acceleration and which is related to information access It will be related to the same slope i.e. what is the slope here, positive and here what will be the slope and it will be positive This thing must have come to us when Velocity Now the next two cases are increasing Ali Mosham and Mohammad Ali, any question of yours if so you can do that later okay right now listen to this thing for now so that the next I asked you a question from the graph You can answer the related questions So now next we have two more graphs which four and fifth you could say is a

18:42 reverse way honge velocity along wa time along x now those graphs This is also the shape of the graph of decreasing velocity This is because with the increase of time the velocity increases The overall value is decreasing and this is also You can also see in the graph that The value of velocity decreases as time increases If both the graphs are decreasing then We are about velocity but the graph is a curve What will you say, velocity is decreasing Non-uniform velocity is decreasing If it is non uniform then what is the difference between the two There is a difference, now let's see what happens to the slope See in this case the angle we already have is 90

19:28 was close to and approaching zero here it means what is the angle doing Decreases but is the angle greater than 90 And in this case, look here at the beginning It is close to zero and slowly reaching 90 getting closer means the angle is increasing But is the angle greater than 90? If the angle is greater than 90 in both cases So what is the slope negative so I'll write Is the slope negative in both cases? The graph is a curve, the angle is changing, the slope is changing is variable here too Now inside the first case we have the variable Slope is increasing, angle is decreasing, zero is approaching it means the slope is inside the decreasing and last case if we See the slope is approaching angle 90 e increasing and the information slope of

20:16 the same acceleration means this Negative Of Variable and Decreasing Acceleration There is a graph above this you guys can see the graph These are the graph numbers and Si Five was positive Variable Decreasing Acceleration and Six is negative variable and decreasing acceleration and lastly we will write it here So what will you write this negative is the acceleration variable other than negative is also now decreasing or Increasing Look here the angle is increasing So this is the graph of increasing acceleration If it happens then means graph number six and sen this Both of these are for non-uniform returns

21:02 Graph is non uniform returns and these two non uniform returns What is the difference in graph number six which is the [ __ ] creasing and the graph number The retention in intake is increasing Ruby Yasin to the slope of Six and Seven look again in six you see in the beginning that our angle is large and after in where we draw the tange our angle If it is decreed then in both the cases you Let's see if we have an angle that is 90 degrees Greater is the album in both cases The graph is f is six or s is the slope

21:47 It is negative, one thing has been confirmed but The difference of angles is in graph number six Angle is going to decrease later But in graph number seven the angle is initially It is close to zero and later to 90 What does this mean the angle is increasing This is the difference between the two would be that the slope we have inside both of them Within six she is declining and What is increasing consumption doing about this? Let me tell you again the last lecture I told you in my book that our slope This happens which we call another name of gradient. also give this equals theta and we know that 0° 90° and 180° is the greater of the three angles than 90

22:38 what is tan0 it is infinity or not that which is there is also zero and that which is not there is also 180 It is zero, which means that our angle is 90 degrees The closer it is, the greater will be the slope and The closer the angle is to 180 what is that much slope Less If there is one more thing we should know The thing that came to us was the angle grater in question. Dan 90 explain this, see the tent You guys are drawing the angle of that tension We have to see from the positive x axis if I am from graph number six This is the line that I drew inside, I mean If you look at the angle from the positive x axis, this what is the angle or is the angle greater than 90

23:25 What will be the negative slope Exactly Ali Raza, whatever you are saying, we are like this can say and we have in both cases I Should I talk here or should I talk here? In which case the angle is positive x What is greater than 90 according to the axis so what is the slope is negative because What is not in the first quadrant is positive and as soon as the value exceeds 90 If the value of 10 is negative then it will be greater If the slope is also negative then the graph of the first half There will be a slope The graph of the second half will have negative slope Laser from Theta 90 in the first half and Theta in half is greater than 90 and I am repeatedly This is what I am saying, this is the angle we are taking If we take it from the positive x-axis then

24:11 Look at the positive x-axis whether the angle is greater or lesser than 90 So this was my velocity time graph now The question I have for all of you is your book related to it's okay you guys can give it to yourself whatever you have There are note pads, draw it there okay so that's your practice I've Basically what you want to ask people is the graph you want to ask me about the shapes of graph I will tell you what the case is and what is the case that a body which we throw vertically upward Now if we move the body vertically upward For throw, you guys can calculate the distance time displacement time speed time and

24:56 Draw velocity time graph I am repeating that you have done a The object is thrown vertically up and the For that you raised your body vertically upward You guys have to draw the graph for the distance Time Displacement Time Speed ​​Time End Velocity Time Graph ok you had another question about graph see the area when the graph is curved The graph we have here is 4 5 6 and Sen, when the graph is a curve, then the The area will come after dividing the total area because this is the shape you are seeing This shape can be any kind of curve. It can also be the fourth part of the circle and

25:43 If it is not possible then what do you do about it Overall divide which is practical There is a way and you guys find it by dividing it Let's do total area but in MCQ So you guys don't have enough time to figure out what divide and then go and do this So in MCQ, the method would be like this that you solved it by approximation all you have to do is that if the graph is a curve then you take a straight line and What is the triangle formed below, its area Now find the overall area is more than the area of ​​the triangle, whichever Your answer will be your calculated area. what will happen will be greater than that but Inside the displacement time graph Such questions in velocity time graph Very few come where you people has to be calculated inside the curve graph there is area but if it comes then epoxy

26:29 While I was solving that, I would add another one Let me also give you an example if the graph curve is And here you have to calculate the area is the same method, draw a straight line Now calculate the area below which is actual The area was and what is the area of ​​the triangle So now your answer will be calculated The area will be less, examples will come later So we can explain it there as well let's go to the question which We had a case, what was it that I had with you The question was that we have defined an object Throw it vertically upward and remember this I'm talking to a guy inside a plane that this is happening in a plane and that Projectile motion is not simply a ball made an upward throw and hit something above the same point

27:15 After some time we caught the ball also we call height let's say height How much is it which the body has adopted and this After hide the body returns to the same point If we land then which graphs will we draw? First of all we will draw a graph that For this How is the graph of distance and time Now all the concepts that are there now will be We have read it till now, it will be revised later we will draw the graph here Displacement time When both the graphs are drawn then Then here we can see the distance time graph Draw a graph of speed and time using slope can and the slope of the displacement and time graph

28:00 From this we can draw the graph of velocity and time and here's a graph that we can see He will see the extras, he will see the acceleration and time of acceleration and time in this whole case how is the graph If yes, then you have one minute to do all these Draw the graph on your notepad After that you will like what I draw will compare it First of all we looked at the distance time when When we talked about distance I told you what the distance is This distance is basically the total path length that If you calculate the total path length then that distance Now the graph of distance and time will be drawn While doing this, we have to keep in mind that

28:47 The slope of the graph will be the answer to the speed you all know when the ball will If the throw is made vertically upward The speed we have while going upward She creases at the maximum height What happens to speed The point where zero is projected What is speed Maximum when the ball comes back downwards If it is coming then what is the speed while coming down It will increase and when it hits again what will be the ground speed Maximum now keep this thing in mind Draw the first point of the graph The point at which the projection was thrown What was the maximum speed at the point if If the speed is maximum then what will be the slope This means the starting point will be where There the graph will not appear as a straight line

29:32 The curve will come and this graph will represent Why is the decreasing slope called because the top Our speed is decreasing as we go this thing here that as time progresses The distance is increasing as we go, but what is the slope doing is decreasing What is the speed at maximum height which is zero This means that by reaching the maximum height, our What will be the slope? Instant zero Now the body will reach its maximum height The speed will come down again, what will it do? Increase now means increasing slope Why will the graph be when the body has to hit Ground speed maximum means this What is our slope going forward from the point If it increases then this will be the shape of the graph This graph will not be a parabola if I draw it

30:18 Let me name that point of projection A Maximum height b point of landing c to I threw a slow maximum at that point Because what is the maximum speed there When you reach the top the slope will be zero then point B our speed is zero slope is zero and when The body will hit the ground again slope What will be the maximum speed now? The displacement time distance and The difference in displacement is that displacement shortest Now see the distance yourself when the body goes upward if she is going up then her Displacement is increasing all the time But displacement is increasing What is Velocity doing to decrease and top up What is velocity, zero means It so happened that the distance from a to b and Displacement graph is same

31:05 from a to b the speed is also decreasing Velocity is also decreasing from a to b Distance is increasing, so is displacement is increasing, at point b the speed is also zero and here the velocity above point b is also it is zero now the difference will come b to c body when What if she comes back to the ground? Will the displacement increase or decrease? will it start again why is it starting again will come towards the point at maximum height The displacement is maximum and as The body will start coming down due to displacement The value will start decreasing, which means the point The graph from B towards C will be It will be exactly its mirror, turn it upside down then the graph from B to C will be this what is the difference The difference is that the B to C distance is increasing

31:53 but B to C displacement is less and the talk of slope The slope will be exactly the same from B to C The slope is increasing and here also B to C The slope is increasing i.e. above point A Velocity maximum is zero at B and also at C The maximum this graph will be is the displacement and Now comes the speed, time and velocity of time The difference between time, speed and velocity is the same is the speed scalar and the velocity vector is not speed sign sensitive but Velocity is sign sensitive, what does it mean Speed ​​through out will remain positive but Velocity will be positive in the first half and Going up negative in the second half If velocity is positive then while coming down velocity is negative because we are moving upward Let's take the vector as positive and down word

32:40 If we take the vector negative then the speed If I draw the graph then when the body What is the speed at that point when it was thrown maximum so what is the speed here maximum So speed over point and projection What is the speed above the maximum point B Zero so what is the speed here zero now What will the graph look like? Remember, the graph will be here. Why straight line because speed overall Change is happening in uniform when the body goes upward towards us or body comes down word we say acceleration is equal to g and what is g 99.8 meters per second per second i.e. every decreases as it goes up to 99.8 in seconds And it means that it will increase as it comes down Slope of Speed ​​and Time Graph is Uniform

33:26 So what will be the first graph, why is it downward The speed is decreasing, after that what will increase the speed because the points A is the projection of a point and C is the point of Landing speed above these two points maximum and point b is the maximum height at What is speed? It is zero. Now let's talk about velocity. in the same way as the speed above point A is the maximum. Similarly, above point A, your Velocity is also maximum and positive now How positive is this point a here What is our angle above, it is 90 is less than degree it means slope here If the velocity above this point is positive then so is the velocity what will be the positive value above point b what is our slope zero means a

34:11 Maximum above the point but towards B What value do we have, it will become zero If it goes then the velocity is zero above point B and what will be the graph here also straight line why is acceleration equal to g and that is constant and the velocity-time graph what is slope Acceleration Ruby Yaseen Distance Time The graph cannot be straight because The slope of the distance time graph is the speed and The speed is decreasing as we go up and down If it is filling up then the thing which is filling it up should be less Its slope is coming closer to us I can't get into straight line form now If we come from B to C then look above the C point The one who asked the slope question was wearing a hijab Also see that above point B and point C

34:57 Our angle is close to 90 slope maximum This means the velocity is maximum difference What is this laser at a point at an angle of 90 See, the angle you have here is 90 degrees What is greater, it means above this point If the velocity is not positive then it will be negative The graph here will be the difference of point c that the speed at a and c is positive but here At a the velocity is positive but the speed What is the velocity at point c? It is negative so what would the graph be here also state line because going up going down is the acceleration constant of g Equally let me repeat that the graph from b to c why did it go into the negative half because b to c If we go towards then at every point

35:43 Our angle is greater than 90 degrees and if the angle is greater than 90 then the slope is negative and the displacement time what is the slope of the graph velocity so b To see what will be our half, negative half Now let's move towards acceleration What would the acceleration graph look like? The slope of the displacement time graph is given by our has velocity similarly velocity time Slope acceleration of the graph hey ryan khan let me repeat this again I will repeat the speed, time and velocity time to this Listen and see where the speed and distance will come from slope of the time graph When we threw the body from that point The speed above was maximum then point A

36:29 What is the maximum speed when the body reaches maximum height above point B If the speed is zero then we are looking at point B that the slope is zero the angle is zero if the angle If the slope is zero then the speed at this point is also zero Zero practically like this now body when B to C If the speed comes back towards the ground Now the speed increases if you increase if it does then what will be the graph, it will be upward will it increase and why will it increase because above point C the speed has again increased what is going to happen maximum and if we air Ignoring friction, move to A and What will be the value of speed on both sides at C those beans If we talk about velocity then velocity A to b is similar like speed up The speed also increases as you go up

37:15 The velocity also increases as we go up Sorry the velocity decreases as we go up The velocity is low but it is positive look at the thing that a to b velocity and a to b speed is similar The difference comes from B onward because when the body Coming down again after reaching maximum height starts then first if the velocity is upward so now what is the velocity downward if The velocity going up is positive because If it is a vector then what is the velocity while coming down is negative because of this b to c is our half what will happen is the negative half and this is negative would be representing velocity and The more magnification it is at the A point, the more Magnitia or the direction of upward fatal velocity

38:03 displacement which occurs along the body Displacement If it is upward then what is the velocity vector? will be upward Now let's go to the extension time I will ask you guys the question of time I will show you a graph of four different colors by Here is a graph I am drawing in white I'll name it Alpha I will draw the second graph which is the option I'm from Green and the shape of that graph is mine I have this one, I'll name it beta I am drawing option in third option

38:48 Pink So the shape of that graph is that first it the graph here is in the negative half and then that graph In the positive half and this pink graph this is graph c and i am the last graph i draw I am doing I am in yellow, the graph shows the first positive half and then the graph is in the negative half If it is gone then these are four graphs, you have to tell What would be the acceleration time graph I will draw these separately for you. for ease of for this graph which I have selected as an option Di that I have inside the positive half

39:36 which is represented by white did the second The graph that shows the beta option I represented it as Green From and overall inside the negative half we have Is Charlie, who I drew from Pink first in the negative half and then in the positive In the half and the last graph that I drew Kiya Yellow itself made him in the first positive half and then the negative half I see the hint in front of you give correct answer as per it and If it is beta then the answer is correct neither

40:23 answer d is correct correct answer is beta we have the graph of beta It is correct, I even gave you a hint that the slope of velocity time graph is Acceleration Now see for yourself what we have What is the slope of the velocity-time graph is the slope of the velocity-time graph through out is negative if I go from point A to point B So when I talk about it, this is my angle This angle is 90 with the positive x axis. what is greater it means a to be our what is the pass slope negative so here start if this is point a and this If point b is then a to b slope is negative

41:09 Now if b comes from c then if b comes from c then Here also if you look at the positive x axis look at the angle so what is the angle still 90 Greater than Degree and in the Fourth Quadrant is going in and we know that the seconds And what is the slope within a fourth negative this means that the angle from b to c is again greater than 90 then what will be the slope negative so if the slope is negative then b to c onward also slope negative its through out what will be the acceleration that we have It will be equal to negative acceleration There may be another way to tell you this explains yes we don't have option c in this case Option C would be there in this case that

41:56 First, our slope will be negative. and what is the slope after that, that is positive be like the graph of speed-time if this Velocity time like speed time graph If there was a graph then your Charlie option would have been there that first what is the slope negative and then What is slope? It's positive. Now, in another way. Understand why I said overall negative Let me tell you one thing, all of you listen to me When we throw the ball upward did we throw the ball upward and We caught the ball again after some time Overall we have the acceleration What is the direction when we throw the ball upward threw and caught the ball again a to b and b to c what is the direction Off

42:43 Acceleration Sad Fajar V Uniform Change Ho It is happening and the uniform change is not seen If these velocities are seen to be uniform then Here is Overall Velocity's Change Uniform The acceleration is uniform and you know that Which action is action due to gravity so this is negative a which if When I talk about magnitude then this Basically if it is negative then the overall the uniform was yes absolutely now everyone's answer is correct overall If there is acceleration it is downward then what going up and coming down acceleration is changing its direction is it going up and coming down acceleration is changing its direction

43:28 No, when we lifted the body upward Even when the body was thrown upwards The overall access we have is down word is and body when back from maximum height It is coming down but we still have it Acceleration is downward toward Earth because we know that acceleration is along the direction of force If acceleration along the direction of If there is force then which force is here Gravitational force is Gravitational force what is down word and its meaning Acceleration is also down word so if the acceleration is down near us if it is a word then its meaning is even while going

44:14 Acceleration will remain the same even when coming If there is acceleration then if the acceleration is negative while going So what overall will we take from him when he comes The negative only will take Aran you are absolutely right overall if If you are asked about net displacement then that Zero only The graph which is correct in this case would be what if we had this acceleration And if there is time then what is the through out acceleration is downward so through out acceleration will it be negative c occurs when the graph speed-time if the velocity time graph is If the shape of the speed-time graph is the same, then we We will have C option

45:00 Now this will be the graph, you know this graph how should the draws be are now Coming to the question, we can understand this from a graph How to calculate distance and displacement You guys can calculate the question and the question is how do we plot these graphs The distance calculated in how to do Now from a single graph we can have multiple to the question will see the graph we have velocity and I will first draw the shape of the time graph. should I mention the value 0 5 10 15 20 and this is point 0 let's say this is 10

45:45 Unit of second and time per meter The shape of the second graph is in front of you from 0 to 5. The graph is now in front of you, the velocity Time graph now in multiple questions to you The first question I will ask is simple: Do you Calculate whether the According to our total distance what is My second question to you is about this graph is inside calculate the distance Covered Vid Uniform

46:34 Velocity this is my second question My third question to you is this: find the Distance Covered With Uniform Returns Ask these three questions and then ask you again A different kind of answer from these questions Make a question for you I will ask you to give total answers to these three questions first. Let's see the answer for distance, what will come if We can calculate the total distance in this graph. If you calculate it then see what the shape is This is the overall shape that we are getting

47:20 it is a trapezium and the total of the trapezium The distance is whose total area is it equal is half sum of parallel sides into perpendicular Distance Between the Parallel Sides Now what is A and what is B here? whether you call it A or whatever above This is the side, tell it to him, it's your wish I'll call this one below A this one and this one in between I call this perpendicular distance I give A now put the value here a b and a of a how much is A 20 how much is B whatever is B 5 and 15 will be the difference between these two. Then 5 more How much distance will be covered in 15 minutes 10 will come or 10 will come and what is a a hai

48:09 equal to 10 so this is 5 30 * 5 150 Meter then we got the total distance 150 meters next I asked you that How much distance was covered by the uniform From velocity, see which half If it has uniform velocity then basically If I have this point, this is a, this is b, this is c and this is d so b to c we're looking at that the velocity we have is uniform This means that what is beneath it This will be the graph of uniform velocity The graph will be this, this can also be called a question like this could that uniform velocity or when What is acceleration zero so in this case if I look at the shape what is it so what shape will come to me

48:57 For a rectangle, the distance which is Covered by uniform or constant velocity If it is found then it is a simple one rectangle is base into height then rectangle what is the base of 10 and we have its height what is it, that too is 10 so it will come to 100 meters And the last third question that I asked you was this How much distance was covered by the uniform In returns we know that retired when does it happen [ __ ] is formally declining For uniform reta then where is the velocity is decreasing from c to d then c to d The graph of this will be negative acceleration might be representing so here we

49:43 What will you do to find the area of ​​the triangle and what is the base of the triangle from 15 25 and what is the height 10 so 10 / 2 5 * 5 25 meter It has become simple if you distance yourself from us Now I am making changes to this question I will ask the question in the same form Get an idea from that as to what can be made That vat Fraction Of distance is Covered with zero axle

50:30 Or it can also be called uniform velocity. could i ask you why Fraction of distance i covered with zero Acceleration Now your answer in fractions Now I will understand the question, I will understand the fraction I asked you what fraction of distance I covered with Uniform Acceleration Now let's see how to solve this I asked you what fraction of distance is covered with uniform Acceleration whenever fractions are involved what do we do to solve this for you People take ratios because they ask for fractions Now what should I take from you? what fraction of distance i covered with

51:15 you will take uniform acceleration up Distance covered with zero acceleration happened and below what will you take you total If you take the distance then you will know what part of the total distance covered by uniform velocity or zero The distance covered by acceleration is What was it from zero acceleration to 100 meter because uniform velocity is zero So the numeration comes to 100 and the total what is the distance 150 zero should be cancelled if we go then what will be our answer 2 diva ba 3 to the extent of the distance is covered with zero If you know what is acceleration then How do you want to solve it The example is in front of you, if I ask you

52:02 asks what fraction of distance I covered with positive acceleration then what is your answer hota wat fraction of total distance i covered with positive acceleration now my question was that We have to calculate Fraction Of Distance With Positive acceleration is, first of all, You will see which part of the graph is positive this is about acceleration this is from zero to f this is Positive acceleration and positive expulsion What is the area of ​​and what is the area of ​​negative extension if it is equal then what will you do, they will take it up the distance that is due to positive acceleration and Below we will take the total which is the positive one

52:49 How much is 25 and what is the total from 150 what will be the answer 1/6 This is a form of question which is related to fractions. we may be asked in the form of now i I will give you practice questions velocity time of displacement From the graph, if we calculate the displacement if you want to do it then how much if it will be how we can Calculate Displacement from Velocity Now we can see the graph of this app if If you were asked what we did first The answer in that would be that the distance is

53:34 Same displacement graph over positive half inside the yes you are asking about its extension time How will the graph look like, its action time graph See what shape it is will be a to b what is the extension positive then a to be positive the graph is uniform This will be any non-zero value of that from a to b b to c What is acceleration zero because What is velocity, what does it mean What happened was that this interval is from b to c, this interval what will be the acceleration we have inside What is the 2D acceleration when the speed becomes zero negative and has exactly the same value as

54:19 If the key is positive then it means the graph is now will go to the negative half and c to d If the acceleration is negative then a to b positive exponent b to c zero and c two negative Extension: Let us now talk about displacement we started to think that from these graphs how to find displacement Now the graph for displacement is I will change it a little bit so let's have a graph between velocity and time in these points We give names to these zeros that we have is this 5 or 10 or 15

55:10 20 this 25 this 30 and this 35 Now I have drawn a graph for you. There are two things in this graph that we need to calculate The examiner asks me to do it, he says that Calculate the angle of this graph in Accordingly what is the total distance and this Calculate the probability that the what is the total displacement If yes then the answer of both will not be same Why the graph that was drawn earlier was only was in the positive half and this graph was positive is in even half and this graph is in negative half here also if the value of velocity is If it is positive then the value of velocity here I will tell you how negative it is The value is also 10 and this value is also 10

55:59 Now what will be the total difference between the two The three of us to find the distance I will add the area of ​​the shapes if I let me name it I have this point A this b this c this d this e this a this g and this h i will not solve it i will just help you I will tell you what answer you get then the total What will you do for the distance? Area of ​​triangle Which triangle is A plus after that cd plus will do distance Triangle is always added CD and the next shape after that is If it is a trapezium then the plus area of

56:45 What is trapezium and trapezium e a g a So when we take the sum of all three, the total distance will be It will come now, I want displacement now Algebra will take the area of ​​upper half as positive We will take the area of ​​the lower half as negative, then the difference What will come then this will be the area of ​​triangle A C now here it was positive but here Now what will come negative and which triangle Whatever shape is formed in the area, here it is a triangle Triangle CD positive again now here The area of ​​trapezium will be positive which what is e edge end So practice this yourself I have told you the basic point about how You can calculate distance from a velocity-time graph.

57:32 and displacement can be found So this was the topic of graph, let's move on now We are on the way to revision of equations of motion we will revise them, we will see that What forms are made so that you know How can we use them do that then next topic is equations of motion Now we normally read three equations First v A So in the second equation we have

58:20 is s = v a ps half time a sc and third From the equation we have two times an eV a scr minus Open chord exactly equilateral triangle Even then its formula remains the same I had also mentioned it in the repeat last lecture whether it is a triangle whether it is a triangle is equilateral is isosceles is right angle If it is a triangle then in both cases it is my If it has its base then it is here The base is This one that I have here is the height This here is the height of both of them This will be the formula to find the area Half base into height no difference

59:06 Now this is the equation of motion, now I Basically the equation of motion can be written as I will not discuss it as it is to you I know I see them under the action of gravity Discus Now I will do it under the action of gravity in this Two things come into play, whether the body can move or not is moving upward or the body is moving down word means we call these equations of motion in two ways In the first case if I simply should I write that under the action of gravity its What form will be made then its form is prepared first what will be formed v f = v plus MyGT now comes with two cases under the The action of gravity on your body

59:53 threw vertically upward and the second you You drop your body from a height did so in case of throw you guys know that the final velocity we have it is zero and when a body is dropped if this is done then in case of drop our The initial velocity would have been zero Now if we look at the equation of both of them Which of the two is the first equation of motion? If there is a change in the form then see the answer What will happen when you throw the body then v A What is zero and throwing upwards when If the body goes then the acceleration is negative g What is equal acceleration negative g so we have upward throw What is the acceleration due to negative g v a rho So here v put a row a to negative

1:00:40 If we put g then this equation will be will be made in the form v aa i ikt k is equal to this means here j value put If I do then g and a what is positive g then v a Whose equal will come equal to GT Now let's see what this equation tells us If we look carefully at both the equations It tells us that when the time is in equal intervals If it increases then the velocity will increase equally Time is one, take 10, velocity 10 will come time two is 20 is 30 4 is 40 5 is 50 every

1:01:28 Velocity after 10 m/s is filling up and this is what extension due to Equal change in gravity is the change in velocity go to second equation second equation What change will come to us now? Instead of displacement we write height we will give you the rest what will happen the rest is ours it will come to pass that h e equal to v+-1/2 gt2 now i apply this inside this Look at both the cases and see what the answer will be What is the row in the first case?

1:02:17 vf2g s and next see what is v then what will it become g is positive ha gt Now this formula is important This is a formula, where does it apply when You should be told that we dropped the body So tell me how much distance he covered after 2 seconds If you have covered it then here you can tell the time to put the square of t 4 4 * 10 40 div Baat 20 means after two seconds the The body has been dropped 20 meters away distance covered Now the third will come towards the third equation If we apply in the equation, then What will come + - 2gh = vf2 - v

1:03:05 Now apply it on both the cases in the first case vf02 g = b of s and when is this formula It applies when we are given height and It should be said with what velocity the body I have thrown it for example there is a tower His height is 40 meters, we threw his body did he attain that height in a certain time Achieved Calculate Initial What will be the velocity then this relation will be used To calculate its velocity, and If we look at the second half, inside the second case vi0 is g is positive then the formula will be 2gh = vf2 means the body which is dropped

1:03:51 Kia hit the ground while he was What will be the velocity, this firm will be used and If you look carefully at these formulas, The formula is the same as what we call the Law of Conservation of Looking into Energy How much potential energy we have lost Even with the same kinetic gain the result would be the same So I have written this equation of motion here But did you mention in what form do we have it These can now be written to you by me This is a question I ask these kids every year I am related to these equations so that you can use them can find out what is The question is that we have a lettuce tower what is the height of the hey there is a certain height, from that height I have a

1:04:36 Drop the Ball Did the ball drop from the site? We did two things I want to find one, find one Distance Covered by the Ball after 3 seconds And the other thing you need to calculate is what is that is Distance Covered by the Ball in third Seconds and the purpose is just to give you this question The point is that you have to use both of these You should know the difference in three seconds or in the following seconds and in these third seconds

1:05:23 There is a difference If you want to do it using shortcut then shortcut if you don't know the shortcut then do it other than that You can also calculate this by any There is nothing difficult in this did you see when you were told that the distance covered after seconds so which one did we cover To use relation, use it for this a e equal to half gt The screen changes to a four-second delay after three seconds. After this how much is covered then we have here What will be the value of 10 times what is it take the square and divide it by 90 this is a simple solution 45 meters is now the second half of the distance

1:06:09 Covered by the ball in third second third second what does it mean if nobody Let me tell him the address, I dropped the ball there the time was zero a second passed two seconds passed three seconds passed Four seconds pass so this is from zero to one Your First Second that the first second passed like a cricket match in first over second over third over if Suppose there is a match in which total five players are there The hours match is one in total five hours The team scored 50 then if asked that What would you say was the score in five hours? 50 But the last hour was the fifth in it Let's total score be 15 if

1:06:55 Specifically asked in the fifth wave What was the score? Then you will say 15 only. You will say 15 this was the question here that row to one this Your first and second was one to two, this is yours Second is second and two to three is yours Third is second it means if I get third If you want to calculate the distance in seconds then what do i need to do i need 2 seconds and 3 The difference in distance in seconds will be I will have to find it, that is, if I I will solve this problem as I have third second What will be the distance between third and second Distance means that in three seconds Two seconds difference in what was covered But I'm not telling you the shortcut right now. I will do it using a formula, it will be made

1:07:42 1/2 g t3 sm 1/2 g t2 s 1/2 g what Will the T3 squad come with common - now put the values ​​of t2 in the score yes what is 10 times first third second square then second second square then square of 3 9 minus 4 5 in 10 50 div this will come 25 meters 25 meters that is the distance covered in third second when What did we do? We dropped a ball now. What is its shortcut and this shortcut is This also applies to translational motion will be And this shortcut is exactly like we do with angular motion

1:08:30 I will also read when the shortcut is applied When the examiner tells us to find the distance covered by a Body in a second formula a a e equals two plus a What is Batu A acceleration into 2 times n- 1 Now just apply this shortcut See in your question that our The question was that in n seconds So what do we have for the value of n here? the body was dropped what is zero a What is acceleration due to gravity 10 n put again what is the value of 3 now

1:09:17 solve it yourself 6-1 5 i 10 50 div ba 2 Even then what was the answer 25 So you guys should remember this shortcut I will say this again and again that these shortcuts Only under the action of gravity apply This may apply even if it is not If the motion of the body is linear then you are here but what will you put in the value of v which is given There will be acceleration and here you will put n Your answer will be calculated in seconds The different types of equations of motion Questions come, they are related to this Let's go to our next Our last topic is towards the Laws of Motion Today Before discussing the Laws of Motion

1:10:05 I will talk briefly about the force in that what is force because loss of motion which is basically related to force, whether whether it is first or second or third It's about the Force we should know what is Force Force is the Tendency to Produce and stop What is motion force? It is basically a Any body has a tendency to produce motion within or to eliminate or reduce the that now the force acting on the body is different Who can do MD Cut Online Prep?

1:10:53 See when to use the C equation When and which equation to use on data It depends, let me tell you briefly If you look at these equations, everyone There is something missing in the equation I will tell you this in table form. then I'm back to my topic I will go and solve any numerical problem for you. So the first thing you guys see is that What is given by the data we have? Data gives you information gives us what equation we have Which formula is to be used? These are the five in our equation of motion. variables are being used final Velocity Initial Velocity Acceleration Time and Distance Remember that every equation

1:11:40 Acceleration present in There will be some of the rest of the things There must be something missing from the first equation if you If you see, the final is in the first equation is the velocity is the initial velocity there is acceleration and in addition there is time so if Any such numerical of yours comes in which Distance is not given, it means you You will get a hint that use the first equation It has to be done, go towards the second side ev plus half times a screw in this equation See what Final Velocity is missing If not, then if your data has final If there is no velocity then you got the hint that Will the second equation be used in this? There is some initial velocity, there is some acceleration there is time and there is distance

1:12:25 this is the variable that is present in if If I talk about the third equation, then 2 times a , vf2 - v s Now the data is telling that the time no given it means in the equation We have all the variables except time we're going to be going towards the third If yes, then this is a simple hint that you Know which equation to use Look at the data if the distance in the equation if the first equation is not final There is no velocity, the other variable is seconds equation and if time is not there then other variables hai that means third equation is being used Let's go back to what I started talking about Tha Force

1:13:12 that what is force and what is the use of force What would be the effect on the body You all know about the force that force is the tendency to produce and Stop Motion Tendency to Produce and Stop Motion The more related to the equation of motion The more you question, the more you Practice will be the relation which is the fourth equation of motion and this is called a iktu vati only and Only A is called in proper form This is not it and remember this is in AIT what is this average whose cases we And this average if I write it in this form

1:13:57 hmm p v a ot in t so in this equation you If you look at it, there is no addition to the rest of the variables he is present in all four sections Besides the tendency to produce stop motion We call it force now I talk about the effect of force on the body But what will be the effect of the force Remember that if our on a body rest nearby and if the body which is at rest is apply force ho what would you say suppose this is a car It is in rest position, on this you have clicked any

1:14:43 If you apply force in that direction then you say that its velocity will increase His The acceleration will be positive and the force because if the body in the direction of Displacement is force in the direction of displacement so you can also say that In this case, the work you have done is positive. Now the second case that we have is If the force is applied on a body which is in body motion In remember if a body is in motion And if force is applied on it then beyond this it is totally this The dependence comes on whom The Angle Of At what angle is the force being applied

1:15:30 of his motion Respective now what does it mean Different cases are created if any

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