Question

With what acceleration $\left(a\right)$ should the box in the figure descend so that the block of mass $M$ exerts a force $\frac{Mg}{4}$ on the floor of the box?

• A. $\frac{g}{2}$
• B. $\frac{g}{4}$
• C. $\frac{3g}{4}$
• D. $4g$

Answer 1

The correct option is C $\frac{3g}{4}$

FBD of block is as shown

$Mg=N+Ma$
$\Rightarrow Mg=\frac{Mg}{4}+Ma$
(given $N=\frac{Mg}{4}$)
$\Rightarrow a=\frac{3g}{4}$
The correct option is (C)