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\(=\sqrt{2gh}\ \ \ ....(2)\)
\(⇒h=\frac{v^2}{2g}\)
\(=\frac{4}{20}m=20cm\)