Question

A body is falling from a height h. After it has fallen a height h/2, it will possess

A 10 kg ball is thrown upwards with a speed of 5 m/s. (i) Find its potential energy when it, reaches the highest point. (ii) Calculate the maximum height it reaches.

Read the given passage and answer the questions that follow based on the passage and related studied concepts. When an object is allowed to fall from higher level to a lower level, it gains speed due to gravitational pull, i.e., it gains kinetic energy. Therefore, in possessing height, a body has the ability to convert its height into kinetic energy, i.e., it possesses potential energy. The magnitude of its gravitational potential energy is equivalent to the amount of work done by the weight of the body in causing the descent. If a mass m is at a height h above a lower level, the P.E. possessed by the mass is mgh. The chosen level from which height is measured has no absolute position. It is, therefore, important to indicate clearly the zero P.E. level in any problem in which P.E. is to be calculated. The potential energy of a body may be positive or negative. Based on the above information, Answer the following questions:

A ball dropped from a height of 20 m loses 40% of its energy after impact on the ground. To what height will the ball rise after the impact?

A tennis ball dropped from a height of 2 m rebounds only 1.5 m after hitting the ground. What percentage of its energy is dissipated during the impact?