This is my solution, somehow answer is different when I calculate without using calculus.
Given that oscillation time, T = 1 second, so L = 2m
But, the answer given is 0.004s longer.
Can someone check if my working is right?
The time of oscillation, T seconds, of a simple pendulum is very nearly equal to 2/L , where L is the length of the pendulum in metres. A pendulum is made to have a time of oscillation of 1 second. Find the effect on the time, if there is an error of 2mm in the length.