Question

A billiard ball with a mass of 1.5kg is moving at 25m/s and strikes a second ball with a mass of 2.3 kg that is motionless. Find the velocity of the second ball if the first ball stops when it strikes the second ball.

Answer 1

Answer:

The velocity of the second ball after the collision will be 16.3 m/s.

Step-by-Step Explanation:

Law of conservation of momentum states that the total momentum of an isolated remains the same before and after the collision.

Let: mass of the first ball = m1 = 1.5 kg

mass of the second ball = m2 =  2.3 kg

Momentum before the collision:

velocity of the first ball = v1 = 25 m/s

velocity of the second ball = v2 = 0 m/s

[tex] Initial momentum = m1v1 + m2v2 = 1.5*25 + 2.3*0 = 37.5 kgm/s [\tex]

Momentum after the collision:

velocity of the first ball = v1 = 0 m/s

velocity of the second ball = v2 = x

[tex]momentum after the collision= m1v1 + m2v2 = 1.5*0 + 2.3*x = 2.3*x[\tex]

According to law of conservation of momentum:

Initial momentum = Momentum after collision

37.5 = 2.3*x

⇒ x = 37.5/2.3

x = 16.3 m/s