Question

For a particle executing SHM, the displacement `x` is given by `x = A cos omegat`. Identify the graph which represents the variation of potential energy `(PE)` as a function of time `t` and displacement `x`.

(a) `I, III`
(b) `II, IV` (c ) `II, III`
(d) `I, IV`

Answer 1

Correct Answer - A
Potential energy is minimum (in this case zero) at mean position `(x = 0)` and maximum at extreme positions `(x = + A)`.
At time `t = o`, `x = A`. Hence, `PE` should be maximum. Therefore, graph `I` is correct. Furhter in graph III, `PE` is minimum at `x = 0`. Hence, this is also correct.