Q. When a body moves in a circular path, no work is done by the force since
A) force and displacement are perpendicular other
B) the force is always away from the center
C) there is no displacement
D) there is no net force
Explanation
(a) When a body moves on a circular path then force and distance are perpendicular to each other. Therefore, work done by the force is
$W = F \bullet d\cos\theta$
$= F \bullet d\cos{90{^\circ}}\ \ \ \ \ \ \ \ \ (\because\theta = 90{^\circ})$
$= 0\ \ \ \ \ \ (\because\cos{90{^\circ} = 0)}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.