Question

A mass $M$ is placed on a very smooth wedge resting on a surface without friction. Once the mass is released, the acceleration to be given to the wedge so that $M$ remains at rest is a where

• A. a is applied to the left and $a=g\tan \theta ;$
• B. a is applied to the right and $a=g\tan \theta ;$
• C. a is applied to the left and $a=g\sin \theta ;$
• D. a is applied to the left and $a=g\cos \theta ;$

Answer 1

Answer: (A)

The pseudo acceleration for the body $a^{\prime }=a$
If the pseudo force $Ma\cos \theta ;$ = $Mg\sin \theta ;$, then the body will be at rest, $a=g\tan \theta ;.$
This horizontal acceleration should be applied to the wedge to the left.