Question

A bullet of mass $10^{-2}$ kg and velocity $200$ m/s gets embedded inside the bob of mass $1$ kg of a simple pendulum. The maximum height that the system rises by is_____ cm.

Answer 1

The Correct Answer is : 20
Momentum conservation :
$10^{-2} \times 200 ≃ 1 × v …(1)$
Energy conservation :
v$=\sqrt{2gh}\ \ \ ....(2)$
$⇒h=\frac{v^2}{2g}$
$=\frac{4}{20}m=20cm$