An astronaut is doing physics experiments on the surface of a planet that has the same radius as the Moon (RM = 1.74 x 10 m) but half the mass of the Earth (M = 5.972 x 1024 kg). Suppose he throws a rock vertically upward with an initial speed of v= 31.6 m/s. What is the maximum height the rock reaches assuming the acceleration is constant close to this planet?s surface?