Momentum principle to calculate speed

[shehan1]

1. A satellite of mass 8000 kg orbits the Earth in a circular orbit of radius of 9.5 106 m (this is above the Earth's atmosphere).The mass of the Earth is 6.0 1024 kg.

What is the speed of the satellite?



2. P_f = p_i+F_net + delta t


3. the only thing i knew to try was 2pi(r)/dt

 

[gneill]

Think circular motion, centripetal force, Gravity.

 

[shehan1]

Do i use F = (mv^2)/r ?

 

[gneill]

Well, that's one formula that you'll need. What are you going to use for the value of F?

 

[shehan1]

GMm/ R^2 ?

 

[gneill]

That looks promising. Why not try it?

 

[shehan1]

Thanks that helped a lot!