Car 1 has a of mass 1000kg and is going at 20m/s. Car 2 has the same mass as Car 1 and is stationary. If they collide and travel together as one unit in the same direction as Car 1 was going, calculate the speed of the unit after the collision.
By Conservation of Momentum
Total Momentum Before= Total Momentum After
thus
m1v1+m2v2=(m1+m2)v3
Plugging in the numbers and re-arranging for v3 gives
100020+10000=2000*v3
v3=(1000*20)/2000=10m/s
