Question

A ball of mass 0.50 kg moving at a speed of 5.0 m/s collides with another ball of mass 1.0 kg. After the collision the balls stick together and remain motionless. What was the velocity of the 1.0 kg block before the collision?

Answer 1

Thanks for asking the question!

ANSWER::

Mass of ball , m₁ = 0.5 kg

Velocity of ball , v₁ = 5 m/s

Mass of another ball , m₂ = 1 kg

Let velocity of another ball = v₂ m/s

Using law of conservation of momentum ,

0.5 x 5 + 1 x v₂ = 0

v₂ = - 2.5 m/s

Therefore , the velocity of another ball is 2.5 m/s opposite to the direction of motion of first ball.

Hope it helps!

Answer 2

Ball 1 :

Mass = 0.5 kg

Velocity = 5 m / s

Ball 2 :

Mass = 1 kg

Velocity = ?

We know that,

Momentum of Ball 1 = Momentum of Ball 2

This can be given by the law of conservation of momentum.

Hence we can say that,

Momentum of Ball 1 = Momentum of Ball 2

Momentum of Ball 1 = Mass * Velocity of ball 1

= 0.5 kg * 5 m/s = 2.5 kg.m/s

Momentum of Ball 2 = Mass * Velocity of ball 2

= 1 * v

2.5 kg.m/s = 1 kg * v

=> v = 2.5 kg.m/s / 1 kg = 2.5 m/s

Hence velocity of ball 2 is 2.5 m/s.