Students conduct an experiment to study the motion of two toy rockets. In the first experiment, rocket X of mass mR is launched vertically upward with an initial speed v0 at time t=0 . The rocket continues upward until it reaches its maximum height at time t1 . As the rocket travels upward, frictional forces are considered to be negligible. The rocket then descends vertically downward until it reaches the ground at time t2 . The figure above shows the toy rocket at different times of its flight. In a second experiment, which has not yet been conducted by the students, rocket Y of mass MR , where MR>mR , will be launched vertically upward with an initial speed v0 at time t=0 until it reaches its maximum height. Rocket Y will then descend vertically downward until it reaches the ground.