Angular momentum and its conservation

AI Thread Summary
The discussion revolves around a physics problem involving a rod subjected to impulsive forces and the conservation of angular momentum. The user attempts to determine the velocity of the center of mass (G) after a collision, initially using the law of translating motion but realizes that the fixed axis means the center of mass should rotate instead of translating. They express confusion about incorporating angular momentum and the implications of the rod's length (l) in their calculations. The user seeks clarification on how to express the velocity and impulsive force in terms of the given variables without introducing additional ones not specified in the problem. The thread highlights the complexities of applying both translational and rotational dynamics in this scenario.
tsopatsopa
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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:
\sum external forces = 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
 

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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)
 
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