Why Doesn't Jumping Off a High Cliff Into Water Save You?

  • Thread starter Thread starter Peter G.
  • Start date Start date
  • Tags Tags
    Water
AI Thread Summary
Jumping off a high cliff into water does not guarantee survival due to the immense kinetic energy and momentum involved upon impact. When hitting the water, the body's force is primarily used to break the surface tension, resulting in a significant impulse that can lead to severe injuries. The rapid deceleration from the impact generates forces that exceed the body's ability to withstand them, often resulting in broken bones. This phenomenon highlights the dangers of high falls into water, as the physics of the situation make survival unlikely. Understanding these dynamics is crucial for recognizing the risks associated with such actions.
Peter G.
Messages
439
Reaction score
0
When I was a kid I remember thinking that if you jumped off an incredibly high cliff but fell on water you would survive.

Now I know you don't, but I don't know how to explain why, my guess is:

When you are about to hit the water after a suicidal attempt described above you have a lot of kinetic energy. I am assuming that when you actually hit the liquid surface you use all that energy to do work to deplete the water. Doing work involves exerting a force to cause the displacement of the water so could the Force you exert on the water, force that the water consequently exerts back on you with the same magnitude but with opposite direction be responsible?

Thanks in advance,
Peter G
 
Physics news on Phys.org
Better explanation would be that when you hit the surface of water, all of your momentum is used to break the surface tension of the water and that too in a very small amount of time.

Thus a very large impulse acts on your body which breaks your bones!
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top