A man of mass m stands on a long flat car of mass M , moving with velocity V.If he now begins to run with velocity u, with respect to the car , in the same direction as V, the the velocity of the car will be

Options

A. `V - m u//M`
B. `V - m u//(m + M)`
C. `V + m u//(m + M)`
D. `V - ut(M - m)//(M + m)`

Answer

B

Explanation

Let velocity of car is `V_1 implies` velocity of man w.r.t. ground = `u + v_1`
`implies (m + M)V = m(u + V_1) + MV_1 implies V_1 = V - (m u)/(m + M)`.