State and prove the law of conservation of energy?
Answers
Energy can neither be created nor be destroyed - law of conservation of energy.
For e.g- In a simple pendulum with no friction, mechanical energy is conserved. Total mechanical energy is a combination of K.E and G.P.E. As the pendulum swings back and forth there is a constant exchange between K.E and P.E.
Answer:
Explanation:
The sum of potential energy and kinetic energy of a freely falling object is equal to a constant.
P.E+K.E=a constant
An object of mass 'm' be made to fall freely from a height 'h'. At the start, the potential energy is mgh and kinetic energy is zero because its velocity is zero. The total energy of the object is thus mgh.As it falls, its potential energy will change into kinetic energy.if 'v' is the velocity of the object, then the kinetic energy would be 1/2mv².As the fall of the object continues, the potential energy would decrease while the kinetic energy would increase. When the object is about to reach the ground, h= 0 and 'v' will be the highest.Therefore the kinetic energy would be the largest and the potential energy the least. The sum of potential energy and kinetic energy of the object would be the same at all points.