00:01
This problem we're given the radius of the earth as 6 ,371 kilometers, and the mass of the earth is 6 .0 times 10 to the 24th kilograms.
00:14
The radius of the moon is given by 1738 kilometers, and the mass is given as 7 .2 times 10 to the 22nd kilograms.
00:27
So for part a, we're asked to figure out the density of the earth.
00:34
That density is given by mass per volume, which is going to equal for a sphere.
00:43
3m .e divided by 4 pi rq.
00:48
Plugging in our numbers, we've about 3 times 10 to the 24th kilograms divided by 4 pi 6 .0, oh, 6 ,371, 6 ,371 times 10 to the third cubed.
01:14
So we have to convert from meters to kilometers.
01:19
And that gives us 5 .5 times 10 to the third kilograms per meter...