A railroad flatcar is traveling to the right at a speed of 13.0 m/s relative to an observer standing on the ground. Someone is riding a motor scooter on the flatcar. (Assume the positive direction is to the right.)
(a) What is the velocity of the motor scooter relative to the flatcar if its velocity relative to the observer on the ground is 18.0 m/s to the right? (Enter a negative value if the velocity of the flatcar is to the left.) in m/s
(b) What is the velocity of the motor scooter relative to the flatcar if its velocity relative to the observer on the ground is 6.0 m/s to the left? In m/s
(c) What is the velocity of the motor scooter relative to the flatcar if its velocity relative to the observer on the ground is zero? In m/s