Answer
(a) Topmost point (b) Bottom most point
Work Step by Step
The total sum of potential and kinetic energy remains the same if there are no non-conservative forces acting.
The kinetic energy is minimum at the topmost point because the potential energy is maximum there, so the speed is minimum there.
The potential energy is minimum at the bottommost point, so the kinetic energy is maximum there, and hence the speed is maximum there.
