# Can anyone explain me clearly about the energy and it's changes in Simple Pendulum? Plz!

Mar 22, 2018

See below.

#### Explanation:

The initial strike is done with kinetic energy

$\frac{1}{2} m {v}^{2} = l \left(1 - \cos \theta\right) m g \approx \frac{1}{2} l {\theta}^{2} m g$

along the streaking process

$m {v}_{A} + m {v}_{B} = m v {'}_{A} + m v {'}_{B}$

with ${m}_{B} = 0$ just before and $v {'}_{A} = 0$ just after the strike

hence the graphic reproducing qualitatively the energy transference is 2)