Question

the hanging bib of simple pendulum is displaced to one extreme position B and then released. it swings towards center position A and then to the other position C. in which position does the bob has: a) maximum kinetic energy? b) maximum potential energy? give reasons for your answer. ​

Answer 1

when the bob is displaced till B, the potential energy is maximum, but as it reaches point A, all the potential energy converts into kinetic energy. at this point, kinetic energy is maximum and because there is no force to stop the motion of the bob, it swings forward to a new position C due to inertia. So kinetic energy is maximum at center position A and potential energy is maximum at points B and C.

Hope this helps :)

Answer 2

The extreme positions of the given pendulum are B and C. The centre position is A.

• (a) Maximum potential energy is at B and C because at these two positions, the bob is at maximum height from ground. Kinetic energy at these points is zero.
• (b) Maximum kinetic energy is at A because at this position, the bob has maximum velocity. Potential energy at this point is zero