Does the amount of force an object experience at a high height in a waterfall is same as the amount of force the object experience at a lower height in waterfall? Does change in kinetic energy also lead to change in amount of force applied by object?
Why does it create a much damage when a heavy stone dropped from a height on the ground than dropped from a low height. I know momentum change! But the amount of force applied by object on ground should be same no?, why height matters!i.e F=ma (m-mass of stone a-9.8m/s^2)?
I think impact should depend on Amount of force applied by object? Or momentum?
I can't figure it out, please clear my misconception!
Best Answer
Yes, if by impact you mean force, then the force experienced by the object that is hit depends on the momentum of the colliding object.
There is a formula from Newton's 2nd law, Force x time = change in momentum. If the colliding object is brought to rest $$Ft=mv$$ or $$F = \frac{mv}{t}$$
For the waterfall or falling water example, let's consider the following.
Pouring water from a jug at constant rate (kilograms per second) and stopping it with your other hand at different heights.
The $\frac{m}{t}$ part of the equation is the same, but the velocity of a falling object increases as it falls. Your hand experiences more force from the water when it's further underneath the jug simply due to the $v$ being greater further down.