A loaded freight car of mass 3.0×105kg is initially rolling toward the east at 20m/s. After applying its brakes, it is observed to roll toward the west at 15m/s. Treat the freight car as a single object throughout.
(a) Calculate the magnitude and direction of the freight car’s momentum before the brakes are applied.
(b) Calculate the magnitude and direction of its momentum after the braking period.
(c) Determine the change in the freight car’s momentum, expressing your answer with both magnitude and direction relative to the east.