The gravitational acceleration at distance r from Earth’s center follows g(r)=g0(rRE)2, where g0=9.8m/s2 and RE=6.37×106m. A research aircraft cruises at an altitude of 15\,km.
What is the percent difference between g0 and the actual magnitude of g at that altitude?
a) About 1%
b) About 0.5%
c) About 5%
d) About 0.2%