A railroad handcar is moving along straight, frictionless tracks with negligible air resistance.

A railroad handcar is moving along straight, frictionless tracks with negligible air resistance. In the cases that follow, the car initially has a total mass (car and contents) of 150 {rm kg} and is traveling east with a velocity of magnitude 5.00 {rm m}/{rm s}. Find the final velocity of the handcar in each case, assuming that it does not leave the tracks.