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Momentum (bouncing ball)

Is momentum conserved when a ball bounces off the floor?

I know kinetic energy isn't conserved, but is momentum?

For momentum to be conserved, the Earth has to move in the opposite direction right?


Thanks
(edited 3 years ago)
Reply 1
https://www.physicsclassroom.com/class/momentum/Lesson-2/Momentum-Conservation-Principle#
https://www.khanacademy.org/science/physics/linear-momentum/elastic-and-inelastic-collisions/a/what-are-elastic-and-inelastic-collisions#

If we assume the collision is elastic and the system is isolated, the energy is conserved. If we assume the collision is inelastic, energy is not conserved - some energy is lost to sound or heat or something else.

In both cases, momentum is conserved:
https://physics.stackexchange.com/questions/132756/why-is-momentum-conserved-in-an-inelastic-collision-and-kinetic-energy-is-not-co
Original post by aramis8
Is momentum conserved when a ball bounces off the floor?

I know energy isn't conserved, but is momentum?



Thanks


So for the principle of conservation of energy, what happened to a bouncing ball above the ground which has gravitational potential energy? Is energy conserved or not (perfectly elastic collision)? Newton's third law of motion says that two objects in interaction, exert equal and opposite forces on each other. Newton's second law of motion also says that the net force(F) is proportionally equal to the change in momentum over time.
Base on that you know that there is no change in momentum, because the resultant force is zero.
Reply 3
Original post by ThiagoBrigido
So for the principle of conservation of energy, what happened to a bouncing ball above the ground which has gravitational potential energy? Is energy conserved or not (perfectly elastic collision)? Newton's third law of motion says that two objects in interaction, exert equal and opposite forces on each other. Newton's second law of motion also says that the net force(F) is proportionally equal to the change in momentum over time.
Base on that you know that there is no change in momentum, because the resultant force is zero.

I think you are correct, I should have said total energy.
Original post by aramis8
Is momentum conserved when a ball bounces off the floor?

I know kinetic energy isn't conserved, but is momentum?

For momentum to be conserved, the Earth has to move in the opposite direction right?


Thanks
Practically, there are some losses, but, yes, the Earth does change its velocity. It's such a miniscule change (as its mass is so high), that it's basically assumed not to.

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