The space shuttle orbits 300 km above Earth surface , that has radius 6400 km . What is the gravitational acceleration experienced by the space shuttle ? Answer is 8.9 m/s^2 . 

I'm trying to equal mv ^2 / r = mMG/r^2 , where v^2/r is "a", so that I get a= mMG/r .. and I put r= 6400+300 but it isn't correct.. 

just a hint would be great , thank you in advance!

 

Edited August 26, 20178 yr by Sara Taboni Miller

Think it requires: mg=(mMG)/r^2

and

ma = (mMG)/(r+300)^2

not 100% sure though. Generally doesn't seem like you have enough knowns from only the information provided.

You already have ma = GMm/r^2

M is the mass of the earth. You know the radius. G is a constant.

Thanks a lot! Got it now !