Physics

Problem

Two identical smooth spheres

A

and

B

, each of mass

m

, lie on a frictionless horizontal surface with

B

in contact with a rigid wall. Sphere

A

is projected towards

B

with speed

5\,\text{m\,s}^{-1}

. The coefficient of restitution for collisions between the spheres is

0.8

, and between

B

and the wall it is

0.6

. After

A

has collided once with

B

B

has rebounded from the wall, and the spheres have collided once more, what is the speed and direction of sphere

A

? a)

4.0\,\text{m\,s}^{-1}

to the left b)

2.4\,\text{m\,s}^{-1}

to the right c)

2.4\,\text{m\,s}^{-1}

to the left d)

0.5\,\text{m\,s}^{-1}

to the right