What is the orbital radius and speed of a synchronous satellite which orbits the earth once every 24h?

Answer 1

synchronous? Would it travel one revolution per day?

Period=24 hr=24*3600seconds

speed=2PI*radius/period.

Now we know gravity is the attractive force...and it equals centripetal force.

GMeMs/r^2=Ms*v^2/rad

GM3Ms/r^2=Ms (2PI radius/period)^2/radius

and you can solve for orbital radius with a little algebra. Then use that to solve for speed.