Homework Help: Horizontal velocity required to launch into orbit?

1. Nov 13, 2009

fattydq

At what horizontal velocity would a satellite have to be launched from the top of Mt. Everest (elevation 8848 m) to be placed in a circular orbit around Earth?

I'm not sure where I'd start here, any tips?

2. Nov 13, 2009

Delphi51

All circular orbit problems begin with
Centripetal force = Gravitational force
Fill in the detailed formulas and solve for whatever you want.

3. Nov 13, 2009

fattydq

What are these "detailed formulas" searching online it seems there's many formulas related to these forces?

4. Nov 13, 2009

Delphi51

For centripetal force, you have your choice of F = mv^2/R or
F = 4π²mR/T². If you know or want to find v, you use the first one. If you know or want to find the period T, use the second.

For the gravitational force, you must use the formula that gives the force exerted by one mass (the Earth) on another (the satellite).
Fc = Fg means that the centripetal force holding it in circular motion is provided by the gravitational pull of the Earth. Fc increases with speed, so if it is going too fast Fc will be too large for the Fg to hold it in circular motion.