What Stops a Falling Rock at the Atomic Level?

In summary, potential gravitation states that as a rock falls, its potential energy is converted into kinetic energy. The rock's height upon being released determines the amount of kinetic energy it has when it hits the ground, balancing out the potential and kinetic energy. When the rock hits the ground, gravity still pulls on every moving atom, causing heat to be created on an atomic scale. However, the electrostatic bonds in the ground and rock are strong enough to prevent the rock from falling further into the ground. This results in the ground around the rock becoming warmer. Additionally, the rock's momentum and mechanical energy change due to the stronger electrostatic forces and the conversion of energy into heat, vibration, noise, and deformation.
  • #1
jammiecg
1
0
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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  • #2
The electrostatic bonds in the ground and rock are strong enough to prevent the rock from falling further into the ground.
 
  • #3
The ground under and around the where the rock came to rest will be warmer then it was before the rock arrived.
 
  • #4
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:
 
  • #5


I can provide an explanation for what stops a falling rock. When a rock is dropped, it begins to accelerate due to the force of gravity pulling it towards the ground. This acceleration is the conversion of potential energy (stored energy due to its position) into kinetic energy (energy of motion).

When the rock hits the ground, it stops because it has transferred all of its kinetic energy to the ground upon impact. This means that the energy is no longer in the form of motion, but instead, it is converted into other forms such as sound, heat, and deformation of the ground and the rock.

On the atomic scale, the rock is made up of countless tiny particles, and each of these particles does experience the force of gravity. However, the force of gravity is incredibly weak compared to other fundamental forces, such as electromagnetic forces. As a result, the rock does not continue to fall on the atomic level, and instead, the particles are held in place by the electrostatic repulsion between them.

In summary, what stops a falling rock is the conversion of its potential energy into kinetic energy, and then the transfer of that kinetic energy to the ground upon impact. On the atomic scale, the particles are held in place by electrostatic repulsion, preventing them from continuing to fall.
 

1. What causes a rock to stop falling?

The force of gravity causes a rock to fall towards the ground. When the rock hits the ground, the ground exerts an equal and opposite force on the rock, causing it to stop falling.

2. Can air resistance slow down a falling rock?

Yes, air resistance can slow down a falling rock. As the rock falls, it pushes against the air, causing the air molecules to move out of the way. This creates a force that opposes the motion of the rock, slowing it down.

3. What role does mass play in stopping a falling rock?

The mass of a falling rock affects how much force of gravity is pulling on it. The greater the mass of the rock, the stronger the force of gravity, and the harder it will hit the ground. However, mass does not directly affect the stopping of the rock; rather, it determines the speed and force at which the rock falls.

4. Is the ground the only thing that can stop a falling rock?

No, there are other factors that can stop a falling rock. For instance, if there is water or a body of water in the path of the falling rock, the water can create drag and slow down the rock's descent. Also, if there are other objects in the path of the falling rock, they can also stop or slow it down.

5. Can a falling rock ever stop in mid-air?

No, a falling rock cannot stop in mid-air. The force of gravity will continue to pull the rock towards the ground, and the rock will only stop falling when it comes into contact with another object, such as the ground or water.

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