Answer
a) no change in the period
b) the time period decreases
Work Step by Step
(a) We know that when the elevator moves upward with constant speed, then there is no change in the behavior of the pendulum and hence the time period of the pendulum remains the same.
(b) We know that when the elevator move upward with constant acceleration, then the system behaves as if the gravitational acceleration were large and thus the time period decreases because 'T' and 'g' are inversely proportional.
