HELP!!!!!!

Question

In an isolated system two cars each with a mass of 1000 kg collide Car 1 is initially at rest while Car 2 was moving at 10 ms. they move off together. what is their speed?

Answer 1

Hi Amanda,

Use the conservation of momentum, note that the two cars coalesce after collision and let V be their final speed 

Momentum before collision =Momentum after collision

momentum of car1 + momentum of car2 = momentum of car1 and car2

mass car1*velocity car1 + mass car2*velocity car2 = (mass car1+mass car2)*V

1000kg*10 m/s + 1000kg*0m/s =(1000kg+1000kg)*V

10000 +0=2000V

10000/2000 = V   , V = 5m/s

The final velocity of the two cars is 5 m/s