A 500kg satellite is transferred from a circular orbit 1000km above Earth’s surface to a new circular orbit 500km above the surface. Using RE=6.4×103km and GME=3.99×1014m3s−2, estimate the change in its total mechanical energy (final minus initial).
a) Decreases by about 5.0×102MJ
b) Decreases by about 1.0×103MJ
c) Increases by about 1.0×103MJ
d) Decreases by about 2.0×103MJ