Consider an airless, non-rotating planet of mass M and radius R. An electromagnetic launcher standing on the surface of this planet shoots a projectile with initial velocity v0 directed straight up. Unfortunately, due to some error, v0 is less than the planet's escape velocity ve; specifically, v0 = 0.755 ve. Unable to escape the planet's gravitational pull, the projectile rises to a maximal height h abovethe ground, then falls back to the ground. Calculate the ratio h/R of the projectile's maximum height to the planet's radius.