A sphere moving with velocity v strikes elastically with a wall moving towards the sphere with velocity u. If the mass of the wall is infinitely large, the work done by the wall during collision will be

Q: A sphere moving with velocity v strikes elastically with a wall moving towards the sphere with velocity u. If the mass of the wall is infinitely large, the work done by the wall during collision will be

(a) mu (u + v)

(b) 2 mu(u + v)

(c) (2/3) mu(u + v)

(d) (3/2) mu (u + v)

Ans: (b)