Height where gravitational field is 0.6 times surface value on planet B

[lmm5arual]

Homework Statement

"At what height above planet B's surface (in meters) does the gravitational field intensity become 0.6 times its value on the surface of planet B, given that the radius of planet B is 6.40 x 10^3 km and that its mass is 5.97 x 10^24 kg?

Homework Equations

g=Gm/r^2

The Attempt at a Solution

My work is very scrambled with trying to convert and compare the values and I think my mistake could be in plugging in the new values.

 

[tiny-tim]

hi lmm5arual!

(try using the X² button just above the Reply box )

show us your full calculations, and then we'll see where you went wrong!