## College Physics (4th Edition)

The correct answer is: (j) $3~s, 7~s$
When an object is in SHM, the object reaches maximum speed at the equilibrium point. The object then moves away from the equilibrium point until the speed is zero at a point of maximum amplitude. The object is moving away from the equilibrium point in the intervals $2 \lt t \lt 4$ and $6 \lt t \lt 8$ The correct answer is: (j) $3~s, 7~s$