Dynamics

[sweet877]

From the radius (1740 km) and mass (7.36 X 10^22 kg) of the moon, calculate gravitational field strength for this body.

g = F/m = F/(7.36X10^22 kg)
F = GmM/r^2 = (6.67X10^-11)(7.36X10^22)M/(1740X10^3)^2
What is the big M?

[andrewchang]

do you need it?

[sweet877]

I would think not...but why? Did I use the wrong formula to find F?

[sweet877]

Ah I got it.
mg = GmM/r^2, the small ms cancel out. Thanks!