Brief Summary
This video explores the famous Google interview question about a person shrunk to the size of a nickel and placed in a blender. The video examines various solutions, including using Van der Waals forces, climbing the walls, and jumping out. The video then delves into the physics behind jumping, explaining how smaller animals have higher strength-to-weight ratios due to the square-cube law. The video concludes by discussing the limitations of the jumping solution and how the question, while seemingly silly, can stimulate creative thinking and lead to new discoveries.
- Smaller animals have higher strength-to-weight ratios due to the square-cube law.
- Jumping out of the blender is a possible solution, but it's not as simple as it seems.
- The question, while seemingly silly, can stimulate creative thinking and lead to new discoveries.
Hard Google Interview Question
The video starts by introducing the famous Google interview question: what would you do if you were shrunk to the size of a nickel and placed in a blender with the blades starting in 60 seconds? The video then explores various solutions proposed by people on the street, including hiding under the blades, trying to climb the walls, and using clothes as a rope. The video highlights the common misconception that the interviewer is looking for a correct answer, but emphasizes that the real goal is to assess the candidate's problem-solving skills, creativity, and communication.
How do Geckos stick to walls?
The video explores the possibility of climbing the walls of the blender using Van der Waals forces, similar to how geckos stick to walls. The video explains that Van der Waals forces are weak attractive forces between neutral atoms, caused by temporary charge imbalances. While these forces are too weak to support a human at normal size, they could potentially be strong enough at the scale of a nickel. However, the video points out that humans lack the specialized structures on their feet that geckos and other insects use for climbing.
Do physicists know the answer?
The video then visits a physics building to ask physics students for their solutions to the blender problem. The students initially struggle to come up with a solution, but eventually suggest jumping as a possibility. The video then delves into the physics behind jumping, explaining how smaller animals have higher strength-to-weight ratios due to the square-cube law.
The Square-Cube Law
The video explains the square-cube law, which states that as an object scales down, its surface area decreases with the square of its height, while its volume decreases with the cube of its height. This means that smaller animals have a greater surface area relative to their weight, which gives them a higher strength-to-weight ratio. The video uses examples of horses, dogs, and squirrels to illustrate this concept, showing that they all jump to roughly the same height despite their vastly different sizes.
Tiny Superheroes
The video further explains how the square-cube law applies to muscle strength. It explains that muscle strength depends on the cross-sectional area of the muscle, which scales down with the square of the height. However, weight scales down with the cube of the height, resulting in smaller animals having much higher strength-to-weight ratios. This explains why ants can lift 50 times their own body weight.
Simulating the problem
The video then explores the feasibility of jumping out of the blender using a simulation. The simulation shows that a person shrunk to 1% of their original size would be able to jump 42cm high, which is enough to escape the blender. However, the video also considers the effect of air resistance, which would reduce the jump height to 39cm.
Adding Air Resistance
The video further explores the impact of air resistance on the jump height. It explains that air resistance would have a greater effect at nickel size due to the increased surface area relative to weight. The simulation shows that if the person were to flip onto their side mid-jump, the increased air resistance would reduce the jump height to 22cm, making escape impossible.
The End?
The video concludes by discussing the limitations of the jumping solution. While the simulation shows that jumping is possible, the video argues that the forces involved would be too great for a human body to withstand. The video also points out that shrinking a human to nickel size would have other detrimental effects, such as the inability to breathe and pump blood.
What would happen if you were shrunk?
The video explores the biological implications of shrinking a human to nickel size. It argues that the human body would not be able to function properly at that scale, due to the limitations of the heart, lungs, and brain. The video concludes that while jumping might be the only option for escaping the blender, it's unlikely that a shrunken human would be able to survive the experience.
What interviewers actually look for
The video concludes by discussing the real purpose of the blender question in Google interviews. It explains that the question is not meant to assess the candidate's ability to solve the problem, but rather to evaluate their problem-solving skills, creativity, communication, and ability to address ambiguity. The video highlights that Google has since abandoned the use of brain teasers in interviews, recognizing that they are not effective in predicting job performance. However, the video argues that these types of questions can still be valuable for stimulating creative thinking and leading to new discoveries.
