Question

a bullet having a mass of 10 g and moving with a speed of 1.5 m/s, penetrates a thick wooden plank of mass 90g. the plank was initially at rest. The bullet gets embedded in the plank and both move together. determine their velocity.

Answer 1

By using law of conservation of momentum you’ll get formula for velocity as

v = m1u1 / (m1 + m2)
= (10 * 10^-3 * 1.5) / [(10 + 90)*10^-3]
= 0.15 m/s
= 15 cm/s

Their combine velocity is 15 cm/s