# Physics

posted by
**winterWX**
.

What linear speed must an Earth satellite have to be in a circular orbit at an altitude of 186 km? What is the period of revolution?

winterWX, Friday, February 16, 2007 at 9:36pm

So GMm/r^2 = mv^2/r and I know that I need to solve for v but what do I use for the mass of the satellite?

Do I just plug in values for G, M, m and r (which equals 6.37e6 + 186e3) and solve for v that way???

You don't need to know the mass of the satellite. Both the left and right sides of the equation are proportional to satellite mass, m. It can be canceled out, leaving

GM/r^2 = v^2/r