Q. A body of weight $50\ N$ placed on a horizontal surface is just moved by a force of $28.2\ N$. The frictional force and the normal reaction are
A) $10\ N,\ 15\ N$
B) $20\ N,\ 30\ N$
C) $2\ N,\ 3\ N$
D) $5\ N,\ 6\ N$
Explanation
(b) Frictional force $= f = 28.2\cos{45{^\circ}} = 28.2 \times \frac{1}{\sqrt{2}} = 20N$
Normal reaction $R = 50 - 28.2\sin{45{^\circ}} = 30\ N$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.