Question

Time period of a simple pendulum is 2sec if length is increased four times then its period becomes?

Answer 1

The new period will be double. See below

Explanation:

We know that for a simple pendulum

`T=2pisqrt(l/g)` where `T` is the period, `g` is gravity acceleration and `l` the pendulum lenght

In these conditions, if the new lenght is `L=4l`, the new period `T``

`T'=2pisqrt(L/g)=2pisqrt(4l/g)=2pisqrt4sqrt(l/g)=2·2pisqrt(l/g)=2T`