Question

Two small balls A and B, each of mass m, are joined rigidly to the ends of a light rod of lengh L (figure 10-E10). The system translates on a frictionless horizontal surface with a velocity vo in a direction perpendicular to the rod. A particle P of mass m kept at rest on the surface sticks to the ball A as the ball collides with it. Find
(a) the linear speeds of the balls A and B after the collision, (b) the velocity of the centre of mass C of the system A + B + P and (c) the angular speed of the system about C after the collision.

Answer 1

Two balls A & B, each of mass m are joined rigidly to the ends of a light of rod of length L. The system moves in a velocity v₀ in a direction ⊥ to the rod. A particle P of mass m kept at rest on the surface sticks to the ball A as the ball collides with it.
a) The light rod will exert a force on the ball B only along its length. So collision will not affect its velocity.
B has a velocity = v₀
If we consider the three bodies to be a system
Applying L.C.L.M.