## In This post you will get answer of Q.

A pendulum is executing simple harmonic motion and its maximum kinetic energy is $K_1$. If the length of the pendulum is doubled and it performs simple harmonic motion with the same amplitude as in the first case, its maximum kinetic energy is $K_2$. Then :

Solution:

## Maximum kinetic energy at lowest point $B$ is given by

$K = mgl (1 – cos theta)$

where $theta $= angular amp.

$K_1 = mg ell (1 – cos theta)$

$K_2 = mg(2 ell) (1 – cos theta)$

$K_2 = 2K_1. $