Gather secondary information to predict the value of acceleration due to gravity on other planets.
- The gravitational force on an object is determined by the planet's mass and "radius".
- Subsequently the gravitational acceleration ($g$) would also depend on those factors.
- To find the value of $g$ on other planets we would $F = mg$ and $F = \frac{GMm}{r^2}$:
\begin{align} F_g = \frac{GMm}{r^2} \end{align}
But as $F = mg$
(2)\begin{align} mg = \frac{GMm}{r^2} \end{align}
Now remove $m$ from both sides:
(3)\begin{align} g = \frac{GM}{r^2} \end{align}
Where:
- $g$ is the acceleration due to gravity ($ms^{-2}$)
- $G$ is Newton's Universal gravitational Constant. ($6.67 x 10^{-11} Nm^2kg^{-2}$)
- $M$ is the mass of the planet. ($kg$)
- $r$ is the radius of the planet. ($m$)
page revision: 0, last edited: 06 Jan 2011 12:04