What Stops a Falling Rock at the Atomic Level?

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jammiecg
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I don't understand this, potential gravitation says that if i drop a rock it's energy is converted into kinetic energy of motion as it falls, so that the higher up it is released the more energy it has kinetically when it hits the ground, both balance out the potential and kinetic energy so that no energy is created or destroyed just converted from one form to another, makes sense...
but my question is when the rock hits the ground and stops, gravity still pulls on every moving atom right? Does that mean it's still somehow falling on the atomic scale, creating heat? That can't be true what stops it from falling on the atomic level is it just electrostatic repulsion?
 
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The electrostatic bonds in the ground and rock are strong enough to prevent the rock from falling further into the ground.
 
The ground under and around the where the rock came to rest will be warmer then it was before the rock arrived.
 
welcome to pf!

hi jammiecg! welcome to pf! :wink:
jammiecg said:
what stops it from falling on the atomic level is it just electrostatic repulsion?

there's two questions …

why does it slow down at all? and why doesn't it bounce back to where it started from?

in other words: why does the momentum change? and why does the (mechanical) energy change?

the momentum changes because (as soothsayer :smile: said), when close-up, the electrostatic forces are stronger than gravity

the (mechanical) energy changes because (as Jobrag :smile: said) some of it is converted into heat (also vibration, noise, and deformation) :wink: