An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?
Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate. Why does the bob eventually come to rest? What happens to its energy eventually? Is it a violation of the law of conservation of energy?
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.
An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.
A certain household has consumed 250 units of energy during a month. How much energy is this in joules?
Does the transfer of energy take place when you push a huge rock with all your might and fail to move it? Where is the energy you spend going?