Question

Two perfectly elastic small smooth spheres A and B have masses 3m and m respectively. The lie at rest on a smooth horizontal plane B with B at a distance a from a smooth vertical barrier. The line of centers of the spheres is perpendicular to the barrier. Sphere A is projected towards B with speed u and, after collision between the spheres, B hits the barrier. The coefficient of restitution between and the barrier is 1/2. Find the speeds of A and B immediately after they first collide, and the distance from the barrier of the point where they collide for the second time

Answer 1

what is the mass of B?

Answer 2

it is m, according to the question

Answer 3

draw it for me

Answer 4

To get the velocities right after collision, use conservation of momentum.

Coefficient of restitution is the ratio of the velocity after impact with the wall to the velocity before it hits the wall, so you now have the velocity of b opn the way back. Plot A and B as distance vs time and see where they intersect or solve the simultaneous equations for their position.