A bullet of mass 'm' moving with velocity 'u' passes through a wooden block of mass `M = nm` as shown in figure. The block is resting on a smooth horizontal floor. After passing through the block, velocity relative to the block is
.

Options

A. `(nv-u)/(n+1)`
B. `(n u-v)/(n+1)`
C. `((1+n)v-u)/(n+1)`
D. `((1+n)n+v)/(2n+
1)`

Answer

D

Explanation

Depth of the point from the surface of earth `d=R-(3)/(4)R=(1)/(4)R,g'=g(1-(d)/(R))=g(1-(1)/(4))=(3g)/(4)`