Question

A body of mass $400g$ slides on a rough horizontal surface if the fractional force is $3.0N$. Find the angle made by the contact force on the body with the vertical

• A. $30$
• B. $37$
• C. $45$
• D. $53$

Answer 1

The correct option is B $37$

Contact force is resultant of Normal reaction and friction.

if the angle made by contact force be $\theta$ then $cot\theta =\frac{N}{friction}$ where $N$ is normal reaction which is equal to $mg$ put $m=0.4Kg$ so put $N=4N$ and friction as $3N$ we get $cot\theta =\frac{4}{3}$ so $\theta as36.87$ or nearly ${37}^0$

Option B is correct.