A simple pendulum consists of a 2 kg bob attached to a 1.5 m long string. How much time (in s) is required for this pendulum to complete 2.5 oscillations?

6.15 s

Explanation:

The period of a simple pendulum is given by the equation

where

L is the length of the pendulum

g is the acceleration of gravity

For the pendulum in this problem,

L = 1.5 m (length)

(acceleration due to gravity on Earth)

Therefore, its period is

And therefore, the time taken for the pendulum to complete 2.5 oscillations is equal to 2.5 times the period: