aramis8
Badges: 12
Rep:
?
#1
Report Thread starter 1 month ago
#1
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
Last edited by aramis8; 1 month ago
0
reply
0le
Badges: 21
Rep:
?
#2
Report 1 month ago
#2
https://www.physicsclassroom.com/cla...ion-Principle#
https://www.khanacademy.org/science/...ic-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/qu...ergy-is-not-co
1
reply
ThiagoBrigido
Badges: 17
Rep:
?
#3
Report 1 month ago
#3
(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.
1
reply
0le
Badges: 21
Rep:
?
#4
Report 1 month ago
#4
(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.
0
reply
RogerOxon
Badges: 21
Rep:
?
#5
Report 1 month ago
#5
(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.
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Following the government's announcement, do you think you will be awarded a fair grade this year?

Yes (609)
49.11%
No (631)
50.89%

Watched Threads

View All