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 900 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.​

Answer 1

Answer:

SOLUTION :

Mass of bullet, m1 = 10 g

Initial speed of bullet, u1 = 1.5 m/s

Mass of plank, m2 = 900 g

Initial speed of plank, u2 = 0

From law of conservation of momentum,

m1u1 + m2u2 = m1v1 + m2v2

Since, the bullet gets embedded in the palnk and both move with the same speed, so v1 = v2 = v

So, we can rewrite the equation as

m1u1 + m2u2 = (m1 + m2)v

10 × 1.5 + 900 × 0 = (10 + 900) v

15 = 910 v

⇒ v = 0.01648351648 m/s