A ball of mass m collides with a wall with speed u and rebounds with the same speed. If the mass of the wall is infinite, then work done by the ball on the wall is

Q: A ball of mass m collides with a wall with speed u and rebounds with the same speed. If the mass of the wall is infinite, then work done by the ball on the wall is

(a) mu

(b) (1/2) m u²

(c) zero

(d) 2 m u²