Question

A body of mass $10\text{kg}$ lies on a rough inclined plane of inclination $\theta ={\sin }^{-1}\frac{3}{5}$ with the horizontal. When a force of $30\text{N}$ is applied on the block parallel to and upward the plane, the total reaction by the plane on the block is nearly along (take $g=10m{s}^{-2}$)

• A. $OA$
• B. $OB$
• C. $OC$
• D. $OD$

Answer 1

The correct option is A $OA$

$mg\sin \theta =100\times \frac{3}{5}=60\text{N}>30\text{N}$. Thus, frictional force $\left(f\right)$ acts up the incline.

This $OA$ is in correct direction.