What are the key forces and impulse affecting a basketball's bounce?

AI Thread Summary
The discussion focuses on the forces and impulses affecting a basketball's bounce, primarily gravitational force and normal force during its motion. Participants analyze the relationship between momentum, potential energy, and kinetic energy, noting that a basketball typically bounces back to about 43% of its original height. They suggest breaking down the bounce process into four distinct phases to better understand the mechanics involved. The conversation emphasizes the importance of considering the compression and decompression of the ball upon impact, as well as the differences in behavior between various types of balls, such as a bowling ball versus a properly inflated basketball. Overall, the complexities of impulse and energy transfer during a bounce remain a central point of inquiry.
Michael1974
Messages
4
Reaction score
0
1. What forces and impulse impact on a bouncing basketball?

I understand that it is the gravitational force, when it falls, then the normal force when it is on the way back. Are there any additional powers?

The momentum, I came to the potential energy = kinetic energy, where I got the speed. The impulse I got through F = 0.81 * 9.82 and t = 0,34s = 2,70kgm / s. I have observed that the ball bounces about 43% of the height at which it is released from. How can I link to such impulse and power?

But what shall I write in the discussion? Why the result as it gets, aiming for an A, it must have the nuance and detail, but gets nowhere ..2. mv^2=mgh
p = mv
Imp = F*t
F = mg

3. I figured out the momentum via mv^2=mgh , where I got the speed. I got the impulse through F = 0.81 * 9.82 and t = 0,34s = 2,70kgm / s. I have observed that the ball bounces about 43% of the height at which it is released from. I must discuss why the result is as it is? I truly have no idea.
 
Last edited by a moderator:
Physics news on Phys.org
Consider splitting up the process into four parts, not just two. Instead of "falling down" and "bouncing back", what about "falling down, not yet touching the ground", "smooshing into the ground", "unsmooshing from the ground" and "rising back up, after leaving the ground".

In an ideal world, would smooshing and unsmooshing be mirror images of one another? What about in the real world?
 
I can divide it into four parts, but why the force and impulse impact in the way they do still remains a mystery for me.

Vaguely put, it will be pullen down due to gravity, when it touches the ground, it will continue to be pulled downwards hence compressing, the energy of compression will thereafter convert to potentiall energy and is greater than gravitational force, thus the ball will shoot backwards (v^2 = 2gd, there d is the compressiong upon the ball) because for instance on a bowling ball is very small, so is the energy - umm, does this make any sense or am I completely wrong) and last stage it's flying up.

But again, I don't know what to write in the discussion in my lab, this is the sole result. So any help?
 
If you drop a bowling ball, a properly inflated basketball and an under-inflated basketball on the ground, which one smooshes most? Are you accounting for that in your analysis?
 
Michael1974 said:
3. I figured out the momentum via mv^2=mgh , where I got the speed. I got the impulse through F = 0.81 * 9.82 and t = 0,34s = 2,70kgm / s.
It would help if you were to explain what these numbers represent. It looks suspiciously as though 0.81 kg is the mass of the ball and 9.81 m/s2 is g. If so, you have calculated the impulse on the ball from the ground while it rests on the ground for 0.34 s. What about the impact velocity?
Michael1974 said:
when it touches the ground, it will continue to be pulled downwards hence compressing,
Again, although gravity will add to the compressing, most of it comes from the impact momentum.

Since it is imperfectly elastic, you need to think about the compression and decompression in more detail, as jbriggs suggests.
This link might help: https://www.physicsforums.com/insights/frequently-made-errors-mechanics-momentum-impacts/. See section 4.
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Correct statement about a reservoir with an outlet pipe'
The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
Back
Top