Question

A bullet, of mass 10^-2 kg and velocity 200 m/s gets embedded inside the bob (mass 1 kg) of a simple pendulum as shown. The maximum height the system rises by is ______ cm.

Answer 1

Correct answer is : 20

Momentum conservation :

10^-2 x 200 \(\simeq\) 1 × v …(1)

Energy conservation :

v = \(\sqrt {2gh}\) ...(2)

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