00:01
We have the orbit of the earth is actually an ellipse, but it's very close to a circle, and that the radius is 93 million miles.
00:08
So we want to determine, first of all, its angular and linear speeds for this.
00:14
But first question is, if we have 365 days, find the angular angle formed by the earth's movement in one day.
00:24
So the angle, it will move 2 pi radians every 365 days.
00:35
So it moves 2 pi over 365 radians per day.
00:43
You could also give it as 360 degrees divided by 365 degrees per day.
00:53
And take that off.
00:59
Now part b asks us to give the angular speed in radians per hour.
01:04
So we know that it moves 2 pi over 365 radians per day.
01:11
And we know that 1 day is equivalent to 24 hours.
01:19
And 2 goes into there 12 times.
01:23
So we would have pi over 365 times 12 gives us 4380, and that's in radians per hour...