Question

Find the direction of the reaction force on the block for the figure shown.

• A. $\text{Perpendicular to the plane}$
• B. $\text{At an angle to the plane}$
• C. $\text{Up the plane}$
• D. $\text{Down the plane}$

Answer 1

The correct option is B $\text{At an angle to the plane}$

Since the velocity of the block is down the plane, friction force $\left(f\right)$ will be up the plane. And, normal reaction $\left(N\right)$ is perpendicular to the plane.

Hence, the reaction force is the resultant of $N$ and $f$ which will at an angle to the plane.