Question

The Car A of mass 1500 kg travelling at 25 m/s collides with another car B of mass 1000 kg travelling at a speed of 15 m/s in the same direction After collision the velocity A becomes 20 m/s. Calculate the velocity of car B after collision​

Answer 1

Answer:

velocity of car B = 22.5 m/s

According to Newton's Second law,

momentum of the system before collision = momentum of the system after collision.

let m₁ ( 1500 kg ) and m₂ ( 1000 kg ) be the mass of the two cars and u₁ ( 25 m/s ) and u₂ ( 15 m/s ) be their initial velocities before collision.

and also v₁ ( 20 m/s ) and v₂ be velocities of the cars after collision.

now we need to find v₂.

we have ,

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

(1500*25 ) + ( 1000*15) = ( 1500 * 20 ) + (1000*v₂)

37500 + 15000 = 30000 + 1000 v₂

52500 - 30000 = 1000 v₂

v₂ = 22.5 m/s