question_answer

With what acceleration a should box of figure descend so that the block of mass m exerts a force \[mg/g\] on the floor for the box?

A)  \[g/4\]                 

B)  \[g/2\]

C)  \[3g/4\]                              

D)  \[4g\]

Correct Answer: A

Solution :

FBD of block is as shown, gives \[mg=N+ma\]                 \[\Rightarrow \]               \[mg=\frac{mg}{4}+ma\]                                 \[a=\frac{3g}{4}\]