00:02
For number 69, this little graph shows the acceleration of an object, and we're told it starts with a speed of 60 revolutions per minute.
00:10
So that's the initial angular velocity.
00:13
And we want to know what is its speed after three seconds.
00:17
Well, you can tell it's going constant speed here, so it's not changing its speed.
00:21
It's staying at that 60.
00:22
And then here for this second, it accelerates for radiance per second squared.
00:28
But then it goes constant speed again.
00:30
So if we can just find what the speed is after this one second of acceleration, that will be our answer.
00:38
So my problem is just this second.
00:41
So i'm looking for the final velocity.
00:45
I know the time of acceleration is just one second.
00:50
And i know the acceleration, the angular acceleration, is four.
00:54
I just need to get this in the right units up here.
00:57
It's in revolutions per minute.
00:59
I need that to be in radiance per second...