this is correct, sorry i typed it wrong the question was supposed to say
i've attempted the question as you suggested but my answer is a factor of 2/3 outs maybe you could spot where I've gone wrong as i can't see any mistakes.
E(launch)= 1/2 mv02+ 3mMG/5R
It is required to put a satellite into an orbit with apogee of 5R/2, where R is the radius of the planet. The satellite is to be launched from the surface with a speed vo at 300 to the local vertical. If M is the mass of the planet show that v0=5GM/R (use conservation of...