Hi Everyone I need help for a physics problem: A stick of mass K is lying on a f
ID: 2124480 • Letter: H
Question
Hi Everyone
I need help for a physics problem:
A stick of mass K is lying on a frictionless surface. A small ball of mass N and velocity v collides with the stick in the center of the stick a right angle to the rod. The collision is completely elastic. (Not complete UNelastic)
b) What is the angular velocity around the axis of rotation after this collision? (We cannot assume that the CM of the stick is at it's center)
c) What is the velocity of the center of mass of the rod after the collision? (Given as a 2D - vector).
Thanks for your help!
Explanation / Answer
mass of stick is F
mass of small ball is G
speed of ball is v
according to conservation of momentum we have
F x u + G x v = (F + G) x V
where u = 0 and V is common velocity after the collision
or V = [F x u + G x v/(F + G)]
the above velocity is the velocity of center of mass
let the length of the stick be L
the ball collides at the center of the stick therefore
S = r x theta
where r = (L/2) and theta = (pi/2) radians
we know that
V1 = (2gS)^1/2
where g = 9.8 m/s^2
Also,V1 = r x w
where w is angular velocity
or w = (V1/r)