A 2150 kg railroad flatcar, which can move with negligible friction, is motionless next to a platform. A 257 kg sumo wrestler runs at 5.3 m/s along the platform (parallel to the track) and then jumps onto the flatcar.
(a) What is the speed of the flatcar if he then stands on it?
m/s
(b) What is the speed of the flatcar if he then runs at 5.3 m/s relative to it in his original direction?
m/s
(c) What is the speed of the flatcar if he then turns and runs at 5.3 m/s relative to the flatcar opposite his original direction?
m/s