One railroad car rolls towards another. Describe the properties of the first car that determine its momentum and how it would impart an impulse to the second car.

(newtons first law)

conservation of momentum law states:

momentum before collision = momentum after collision

momentum p (kg-m/s) = mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10 = 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000 * 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg * velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time, momentum is exclusive of external forces and a perfect collision is implied