Solving the Physics Problem: Modeling a Spinning Ball Dropped on Floor

Click For Summary
SUMMARY

This discussion focuses on modeling a spinning ball dropped on the floor, specifically addressing the calculation of final angular velocity considering friction. The user encountered a singularity while applying the work-energy principle, which relates frictional work to changes in kinetic energy. Three methods for solving the problem were identified: Newton's laws, conservation of energy, and conservation of momentum, with conservation of momentum being the most straightforward. The final angular velocity can be calculated using the formula: Omega final = Omega initial / (I + mr^2 / I).

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with conservation of energy principles
  • Knowledge of angular momentum and its calculations
  • Basic concepts of friction and its effects on motion
NEXT STEPS
  • Study the application of Newton's laws in rotational dynamics
  • Learn about the conservation of energy in mechanical systems
  • Explore angular momentum calculations in different contexts
  • Investigate the effects of material deformation on energy transfer during impacts
USEFUL FOR

Physics students, mechanical engineers, and anyone interested in dynamics and rotational motion modeling will benefit from this discussion.

NotMrX
Messages
97
Reaction score
0
Hello

Does anyone know how to model a ball (sphere) with mass spinning with an initial angular velocity that gets dropped on the floor with a coefficient of friction? And find the final angular velocity?

I tried solving the problem but somehow I got a singularity.

The idea I used was the work from friction equals the change in the kinetic energy (rotational and translational) but even after I reworked I got a singularity so i must be doing something wrong.

Thanks for your help.
 
Physics news on Phys.org
Do you mean like a spinning billiard ball or a spinning rubber ball? How much does the ball deform on impact? It seems that for a rubber ball, some energy will get converted to head from the deformation and rebound. Even the billiard ball example will deform slightly during the bounce.
 
There 3 ways to solve problem: straightforward application of Newton's laws, conservation of energy, and conservation of momentum. Conservation of momentum is by far the easiest. The angular momentum of the ball when it is released equals the angular momentum when the ball starts to roll (linear momentum + rotational momentum). You can check your result using the general solution:

Omega final = Omega initial / (I + mr^2 / I)

Example: Spinning hoop - Omega final = Omega initial / 2
 

Similar threads

Replies
14
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
3
Views
3K
  • · Replies 33 ·
2
Replies
33
Views
3K
  • · Replies 47 ·
2
Replies
47
Views
5K
  • · Replies 10 ·
Replies
10
Views
5K
Replies
3
Views
2K