When a ball bounces off the ground, which of the following changes suddenly ?
(Assume no loss of energy to the floor)
Its speed
Its momentum
Its kinetic energy
Its potential energy
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-2 – 2019
Velocity is a vector quantity, having both magnitude (speed) and direction. Momentum is mass multiplied by velocity (p = mv), so it is also a vector quantity. When a ball bounces, its downward velocity just before impact changes to an upward velocity just after impact. Even if the speed remains the same (in a perfectly elastic collision with no energy loss), the change in direction causes a significant change in the velocity vector, and thus a sudden change in the momentum vector.