Question

A truck with mass of 3,250 kg traveling with a velocity of 25.0 m/s hits a car at rest. After the collision, the truck moves with a velocity of 19.0 m/s. The car has a mass of 2,820 kg. If the two vehicles do not stick together, how fast is the car moving after the collision?

Answer 1

6.9 m/s

Step-by-step explanation:

This is a conservation of momentum problem, so the total momentum before the collision must equal the total momentum after the collision.

P = mv

m1v1 + m2v2 (before) = m1v1 + m2v2 (after)

(3250kg)(25.0 m/s) + (2820 kg)(0m/s) = (3250 kg)(19.0 m/s) + (2820 kg)(v2)

Now you can solve for the v of the car after the collision:

81250 kg·m/s + 0 = 61750 kg·m/s + (2820 kg)v2

19500 kg·m/s = (2820 kg)v2

v2 = 19500 kg·m/s / 2820 kg = 6.9 m/s