An earth satellite in circular orbit 1200 km high makes one

An earth satellite in circular orbit 1200 km high makes one complete revolution every 90 minutes. What is its linear speed? Use 6400 km for the length of a radius of the earth. Identify your formula, define all variables used and be sure to show your work. Include the proper units in your final answer and round to two decimal places.

Solution

r = 6400 + 1200 = 7600 km

w = 1 rev/90 min ,

v = ? km/min

Now v = rw = (7600 km/1)*(1 rev/90 min)*(2pi/1 rev) = 1520pi/9 = 530.6 km/min