Question

the ball of mass 10 kg is moving with velocity 10 m/sec. it strikes another ball of mass 5 kg which is a moving in the same direction with velocity 4m/sec.calculate their after collision.

Answer 1

m1u1+m2u2=(m1+m2)×v
=>10×10+5×4=15×v
=>100+20=15v
=>v=120/8
=>v=8
.°. velocity after collision = 8m/sec

Answer 2

Hello Friend !!!


This is your answer..

Mass of first ball, m₁ = 10 kg.
Initial velocity of first ball, u₁ = 10 m/s.

Mass of second ball, m₂ = 5 kg.
Initial velocity of second ball, u₂ = 4 m/s.

We have to calculate the velocity after collision...

ACCORDING TO THE LAW OF CONSERVATION OF LINEAR MOMENTUM, MOMENTUM BEFORE AND AFTER THE COLLISION WILL BE SAME. 
Also, the velocity after collision will be same for both the ball.

So, 
m₁u₁ + m₂u₂ = v(m₁+m₂)
=> 10 X 10 + 5 X 4 = v (10 + 5)
=> 100 + 20 = 15v
=> v = 120/15
=> v = 8.

Hence, the velocity after collision is 8 m/s.

Hope it helps...