Answer
The correct answer is:
(k) $1~s, 5~s$
Work Step by Step
When an object is in SHM, the sum of the kinetic energy and potential energy is constant. The potential energy is decreasing whenever the kinetic energy is increasing, which occurs when the speed is increasing.
The speed is increasing in the intervals $0 \lt t \lt 2$ and $4 \lt t \lt 6$
The potential energy is decreasing in the intervals $0 \lt t \lt 2$ and $4 \lt t \lt 6$
The correct answer is:
(k) $1~s, 5~s$
