Acceleration Due to Gravity on Planets or Moons
Since Fg = mobjectg and Fg = G mobjectmplanet
r2
it is possible to calculate the g for any planet if you know its mass and body's radius.
r = R planet
Ex. 1 Calculate the acceleration due to gravity on the surface of Venus.
Acceleration Due to Gravity at Different Altitudes
Since Fg = mobjectg and Fg = G mobjectmplanet
r2
it is possible to calculate the g for any altitude if you know the surface value.
r = R planet + h
Ex. 2 Calculate the acceleration due to gravity at a position 150 km Method 1
above the surface of Venus.
Ex. 2 Calculate the acceleration due to gravity at a position 150 km above the surface of Venus.
Method 2
Comparing Weights at Different Altitudes
higher altitude
G M1MEarth
M1
g
new
(Re + h)2
sea level
G M1MEarth
M1
g
(Re)2
h
sea level