A 7450kg satellite has an elliptical orbit. The point on the orbit that is farthest from the earth is called the apogee. The point on the orbit that is closest to the earth is called perigee. Suppose that the speed of the satellite is 2940m/s at the apogee and 8400m/s at the perigee.
(a) Find the work done by the gravitational force when the satellite moves from the apogee to the perigee.
(b)Find the work done by the gravitational force when the satellite moves from the perigee to the apogee.
a) work done (by gravity) = potential energy difference. The potential energy at separation distance R = -G M m/R, where
M = earth mass
m = satellite mass
G = universal constant of gravity
Calculate these PE values and sbtract the apogee value from the perigee value. You should get a positive number.
The answer to (b) will be the same as (a) but with opposite sign
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