00:01
All right, so let's say we have a satellite orbiting earth, and we're told its height above earth surface, which is greatly exaggerated here, is 19 ,600 kilometers.
00:14
And so we want to compute the orbital speed of the satellite using a mass of earth of 5 .97 times 10 to the 24th kilograms, and a value of newton's constant, a 6 .67408.
00:31
Times 10 to the negative 11th cubic meters per kilogram per second squared.
00:37
So the distance, the orbital distance, r is going to be the radius of earth, which is 6 .37 million meters, plus this extra height, which we can write as 1 .96 times 10 to the 7 meters.
00:51
And so with all that in mind, our orbital velocity is going to be the square root of g times m over r.
00:58
So 5 .97 times 10 to the 24th times 6 .6 .6 .7 .7.
01:03
67408 times 10 to the negative 11th divided by 6 .37 times 10 to the 6 plus 1 .96 times in the 7th and take the square root.
01:13
This should give us 3 ,917 meters per second.
01:20
And then for the second part per part b, we want to know what's the orbital period of the satellite.
01:25
That was part a...