When a ball bounces off the ground, which of the following changes sud

When a ball bounces off the ground, which of the following changes suddenly ?
(Assume no loss of energy to the floor)

[amp_mcq option1=”Its speed” option2=”Its momentum” option3=”Its kinetic energy” option4=”Its potential energy” correct=”option2″]

This question was previously asked in

UPSC NDA-2 – 2019

Download PDF Attempt Online

The correct option is B) Its momentum. When a ball bounces off the ground, its velocity changes direction suddenly, leading to a sudden change in its momentum.

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.

Speed is the magnitude of velocity. In an idealized elastic collision with no energy loss to the floor, the speed of the ball remains the same before and after the bounce. Kinetic energy (KE = 1/2 mv²) depends on the square of the speed, so it also remains the same if there’s no energy loss. Potential energy (PE = mgh) changes gradually with height and is at a minimum (or zero) at the point of bounce; it does not change suddenly during the bounce event itself.

More similar MCQ questions for Exam preparation:-