Q. A ball is dropped vertically from a height $d$ above the ground. It hits the ground and bounces up vertically to a height $d/2.$ Neglecting subsequent motion and air resistance, its velocity $v$ varies with the height $h\ $above the ground as
A)
B)
C)
D)
Explanation
(a) For the given condition initial height $h = d$ and velocity of the ball is zero. When the ball moves downward its velocity increases and it will be maximum when the ball hits the ground & just after the collision it becomes half and in opposite direction. As the ball moves upward its velocity again decreases and becomes zero at height $d/2.$ This explanation match with graph $(A)$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.