At the Earth's surface a projectile is launched straight up at a speed of 10.1 km/s. To what height will it rise? Universal gravitational constant = 6.673e-11 N m^2/kg^2 Radius of the earth = 6.370e+6 m Mass of the earth = 5.980e+24 kg I know to use the equation U= - (Gm1m2)/ r I also need to take into consideration that r is the radius of the earth and the object is launched at the surface of the earth. However how am I suppose to solve for height when their is no mass of the projectile and what do I do with the speed of the projectile. I originally thought I should consider that U=mgy but that got me nowhere. Any help will be appreciated I'm literally teaching this to myself.