Determine total mechanical energy

[nickb145]

Homework Statement

What's the total mechanical energy of a 400kg satellite in circular orbit 1100km above Earth's surface?

Homework Equations

The Gravitational potential energy U=-(Gm1m2)/r

kinetic energy k=1/2mv^2

The Attempt at a Solution

At first i thought i could do just the gravitational potential energy, then figured out i was missing the kinetic energy. But one problem, i can't remember how to find the velocity

Would it have anything with angular velocity with it?

So i have the gravitational potential energy, just not the kinetic enegry...

 

[rude man]

Equate centripetal force to gravitational force.

Assume Earth mass >> satellite mass.