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Question
The hanging bob of a simple pendulum is displaced to one extreme position B and then released. It swings towards centre position A and then to the other extreme position C. In which position does the bob have :
(i) maximum potential energy?
(ii) maximum kinetic energy?
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Solution
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.
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