Saved Bookmarks
| 1. |
State and proof of work energy theorem |
| Answer» Work energy theorem states that the change in kinetic energy of an object is equal to the net work done on it by the net force.Let us suppose that a body is initially at rest and a force F is applied on the body to displace it through dS along the direction of the force. Then, small amount of work done is given bydW = FdSAlso, according to Newton\'s second law of motion, we haveF mawhere a is acceleration produced (in the direction of force) on applying the force. Therefore,dW = MadS = M dv/st dSOr dW = M Ds/dt dv = MvdvNow, work done by the force in order to increase its velocity from u (initial velocity) to v (final velocity) is given byW = 1/2 mV2 - 1/2 Mu2Hence, work done on a body by a force is equal to the change in its kinetic energy. | |