A 1500 kg car traveling at 15m/s to the south collides with a 4500 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 two vehicles

3.75 m/s

Explanation:

Here's what you know: The car has mass 1500 kg, and initial velocity 15.0 m/s.  The truck has mass 4500 kg and initial velocity 0 m/s.  The final mass is 6000 kg (4500 kg plus 1500 kg, because they stick together) and we are looking for the final velocity.  Using the formula p = mv, and the concept that p before equals p after, the p of the car plus p of the truck equals the p of them together. So, 1500 x 15 + 4500 x 0 = 6000 x v final.  22500 = 6000 v, and v = 3.75 m/s.  The velocity is positive, and the initial velocity of the car was positive, so the two vehicles together are traveling to the south just like the car was initially.

the independent variable, or the one that is intentionally manipulated is the speed.

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000