Angular momentum and its conservation

Click For Summary
SUMMARY

The discussion focuses on the conservation of angular momentum in a system involving a rod subjected to impulsive forces. The rod, with a length of l and mass M, experiences a force P applied at a distance x, resulting in a reaction force PA at a fixed axis A. The key equations derived include the velocity v of the center of mass G expressed as v = (P - PA) / M and the impulsive force PA expressed in terms of l, x, and P. The participant seeks clarification on the application of angular momentum principles in this context.

PREREQUISITES
  • Understanding of angular momentum conservation principles
  • Familiarity with impulsive forces and their effects on rigid bodies
  • Knowledge of translational and rotational motion dynamics
  • Basic equations of motion and momentum
NEXT STEPS
  • Study the derivation of angular momentum equations for rigid bodies
  • Learn about the relationship between linear and angular momentum
  • Explore the effects of impulsive forces on rigid body motion
  • Investigate the principles of fixed axis rotation in mechanics
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators and anyone interested in the application of angular momentum in real-world scenarios.

tsopatsopa
Messages
3
Reaction score
0

Homework Statement


Check out the attached image. A is a fixed axis.
An impulsive force P =FΔT is given to the rod from a distance x. As a reaction to that, an impulsive force PA =FA ΔT is transmitted to A.

The rod has a length l and mass M.


Homework Equations


a. Velocity v of the center of mass G just after the collision. (express in function of P, PA and M )
b. The value of the impulsive force PA (express in function of l, x and P)


The Attempt at a Solution


a. I think the center of mass is supposed to translate just after the collision.
According to the law of the translating motion:
[itex]\sum external forces[/itex] = change in momentum.
So, I did P = PA + Mv
And I can get v from that. (Am I right here?)
What I don't know is: The axis A is fixed ===> The center of mass IS NOT SUPPOSED TO TRANSLATE but ROTATE. If I am thinking of using the angular momentum stuff, I will get a new variable: l (length of the rod). However the question asked if to express v in function of P, PA and M and l is not mentioned.

b. NO IDEA.
I was thinking of using the angular momentum and apply its conservation but if I call the angular momentum, I will get a new variable M (mass of the rod) which is not asked to use to express PA

Looking forward for your help.
Tsopa,
Japan :D
 

Attachments

  • photo.JPG
    photo.JPG
    21.5 KB · Views: 515
Physics news on Phys.org
SORRY, I accidentally put the question in the "relevant equations" paragraph (I thought it was "relevant questions" not "equations" lol)
The questions are:

a. Express the velocity v of the center of mass G just after the collision. (express in function of P, PA and M )
b. Find the value of the impulsive force PA (express in function of l, x and P)
 

Similar threads

  • · Replies 71 ·
3
Replies
71
Views
5K
  • · Replies 17 ·
Replies
17
Views
1K
Replies
17
Views
2K
Replies
335
Views
17K
Replies
10
Views
3K
Replies
23
Views
2K
  • · Replies 18 ·
Replies
18
Views
4K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 4 ·
Replies
4
Views
2K