posted by fluffy .
A 1200.0kg car is moving east at 30.0 m/s and collides with a 3600.0 kg truck moving at 20 m/s in a direction 60 degrees north of east.The vehicles interlock and move off together.Find their common velocity.
Use the law of conservation of momentum. The resultant momentum of the two cars before collision equals the final momentum of the interlocked vehicles, which have a combined mass of 4800 kg.
If +y is north and +x is the east direction, the initial momentum has components
Px = (1200 * 30) + (3600 * 20 cos 60)
Py = 3600 * 20 sin 60
If Vx and Vy are the velocity componensts of the interlocked vehicles,
4800 Vx = Px
4800 Vy = Py
Solve for Vx and V