In the figure shown, friction exists between wedge and block and also between wedge and floor. The system is in equilibrium in the shown position.

Options

A. frictional force between wedge and surface is `mu(M+m)g`
B. frictional force between wedge and surface is `mg`
C. frictional force between wedge and block is `0`
D. minimum coefficient of friction required to hold the system in equilibrium is `(m)/(M+m)`

Answer

B, C, D

Explanation

Tension in the thread `= mg`
Assuming `(M+m)` as a single mass unit, the only external forceacting is rightwards so frictional force
`T=mg`
Normal force wedge and block is zero,
so no frictional
force acts between wedge and block.
At limiting conditions for `(M+m)` system.
`T=mu(M+m)g rArr mg = mu (M+m)g`
`rArr mu=(m)/(M+m)`