Question

Two cars collide and then stick together in an accident, see Figure 1. Car A has a mass of 1000 kg traveling at a velocity of 5m / s while car B has a mass of 2000 kg with a velocity of 2 m / s. What is the velocity of the cars after the collision?​

Answer 1

Explanation:

Before collision

momentum of car A = P1 = 1000×5 kgm/s

P1= 5000kgm/s

momentum of car B= P2= 2000×2kgm/s

P2 = 4000 kgm/s

=> momentum before collision= momentum after collision

situation 1st : if they move in opposite direction

P1 - P2 = (m1+m2) V

=> 5000-4000 = (1000+2000) V

=> V= 1000/3000 = +1/3 m/s

both move with vel 1/3 m/s in the direction of car A after collision.

note:- + sign indicates direction to A

situation 2nd: if the move in the same direction

=> P1+P2= (m1+m2)V

=> 5000+4000 = (1000+2000)×V

=> V= 9000/3000 = 3 m/s in the same direction as before