Question

Two cars are driving at each other in a straight line. Car 1 has a mass of 600 kg and drives at 15 m/s. Car 2 has a mass of 1800 kg. How fast must Car 2 be driving to make the net momentum between the two cars equal to zero?

Answer 1

-5.0 m/s

Step-by-step explanation:

Momentum = P = mv

Pcar1 = (600 kg)(15 m/s) = 9,000 kg·m/s

Car 2 is going in the opposite direction, so its P must equal -9,000 m/s.

Pcar2 = -9,000 kg·m/s = (1800 kg)(v)

v = -9,000 kg·m/s / 1800 kg = -5.0 m/s

Meaning, Car 2 has to be driving at a velocity of 5.0 m/s in the direction opposite to Car 1