- #1

tsopatsopa

- 4

- 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 P

_{A}=F

_{A}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, P

_{A}and M )

b. The value of the impulsive force P

_{A}(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 = P

_{A}+ 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, P

_{A}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 P

_{A}

Looking forward for your help.

Tsopa,

Japan :D