In many engineering uses, the value of �g�, the acceleration due to gravity, is taken as a

constant. However, g is actually dependent upon the distance from the center of the
Earth. A more accurate expression for g is: g=g0(Re/Re+A)^2

Here, g0 is the acceleration of gravity at the surface of the Earth, A is the altitude, and Re
is the radius of the Earth, approximately 6,380 kilometers. What is the value of g at an
altitude of 20 miles in units of meters per second squared?

2 answers

well, uh, g, plug in the numbers!

20 miles = 32.2 km, so

A(32.2) = 9.81(6380/(6380+32.2))^2 = 9.71 m/s^2
Awesome! Thank you so much.