00:01
So when this problem we're asked about the magnitude of the net gravitational force on the moon, we have the sun, the earth, and the moon in the system.
00:10
So the first thing to do to solve this problem is let's just go ahead and draw the top one.
00:17
So there's the sun, moon, and earth.
00:29
So this will be r -e -m, r -s -m, first sun and moon, ours, e -n for earth and moon.
00:40
So we want the forces on the moon.
00:43
So we know that we'll have the force, the earth moon system, and the force from the sun in the moon.
00:53
And then we know that the force, the gravitational force total on the moon, equal to the force from the sun and the moon, plus the force from the earth in the moon.
01:10
And we want the magnitude, so that will be like this.
01:18
This is how we find the magnitude of a vector.
01:25
Okay, and then we know that, um, from the law of gravitation with the force of gravity is equal to gmn over r squared.
01:37
So we'll just plug that in for this.
01:41
So we'll get that the force, magnitude, the force on the moon...