A ball is thrown upwards and caught when it returns. Neglecting air resistance, the speed with which it is caught is
A)more than its initial speed.
B)less than its initial speed.
C)the same as its initial speed.

Question

Quizplus · Accepted Answer

According to the law of conservation of energy, the total mechanical energy of the ball should remain constant throughout its motion.

At the initial point, the ball possesses only kinetic energy, and at the maximum height, the ball possesses only potential energy.

When the ball is caught, it is at the same height as the initial point, and hence the potential energy of the ball at that point is zero.

Therefore, the total mechanical energy of the ball at the highest point and the time of catching remains the same - which means that the kinetic energy of the ball while being caught or at the highest point is the same as the kinetic energy at the initial point.

Hence the speed with which it is caught is the same as its initial speed.

A Ball Is Thrown Upwards and Caught When It Returns