Eli5 If the equation for force is F=ma why does dropping the same object from 2 different heights change how much an object would be crushed?

Question

In science one year, we did a test of dropping a water bottle from different heights over a Pringle, and we had to protect the Pringle with a paper. But how would increasing the height increase the force is the mass and acceleration is the same?

In: 152

Answer 1

Because when you double the height the force (gravity) is able to accelerate the object for a longer time.

Force is not the same thing as energy of momentum.

So when the object falls for twice as long it gains much more kinetic energy.

And that kinetic energy is what you need to protect against, it’s the difference between someone gentle throwing a baseball at you, and a pro pitcher throwing a baseball at you as hard as they can. The second one has way way way more kinetic energy.

Tl:dr “force” does not equal “energy” you can be sitting perfectly still on the ground not moving and still have the force of gravity on you.