Question

A block $A$ of mass $M$ rests on a wedge $B$ of mass $2M$ of inclination $\theta$. There is sufficient friction between $A$ and $B$ so that $A$ does not slip on $B$. If there is no friction between $B$ and ground, the compression in spring is

• A. $\frac{Mg\cos \theta }{K}$
• B. $\frac{Mg\cos \theta \sin \theta }{K}$
• C. $\frac{Mg\sin \theta }{K}$
• D. $\text{Zero}$

Answer 1

The correct option is D $\text{Zero}$

Since there is no relative motion between the block and the wedge due to sufficient friction, the wedge will not move at all. So, the compression in the spring will be zero.
$\therefore \left(d\right)$ is the correct option.