Don't get scared when you hear the word Physics!
posted by Just help please. Homework due in 4 hours on .
A 1500 kg car traveling at 16.0 m/s to the
south collides with a 5100 kg truck that is
initially at rest at a stoplight. The car and
truck stick together and move together after
the collision.
What is the final velocity of the twovehicle
mass?
Answer in units of m/s

The direction of the car&truck, stuck together, remains south.
For the final speed Vf, use the conservation of momentum law
Initial momentum = Final momentum
1500*16.0 = 6600*Vf
Vf = 3.63 m/s 
thank you.