A freely falling object eventually stops on reaching the ground. What happens to its kinetic energy? Open Answer »
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why? Open Answer »
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero. Open Answer »
Calculate the work required to be done to stop a car of 1500 kg moving at a velocity of 60 km/h? Open Answer »
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? Open Answer »
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? Open Answer »
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. Open 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. Open Answer »