Question

A mass $m$ is placed on a wedge (triangular block) of mass $M$. The wedge moves on a smooth horizontal surface what should be the force $F$ applied on the wedge to the right, so that $m$ remains stationary with respect to wedge. (Ignore any friction)

• A. $g \tan \theta$
• B. $m g \cos \theta$
• C. $(M +m) g \tan \theta$
• D. $(M +m) g \text{cosec} \theta$

Answer 1

Answer: (C)

From figure, $m g \sin \theta=m a \cos \theta$

$\Rightarrow a=g \tan \theta$
$\therefore $ Force, $F =(M +m) a=(M +m) g \tan \theta$