00:01
We're asked a couple questions about circular motion.
00:05
The first part of the question asks, what direction does an object moving in a circle have the centripetal force point pointed toward? centripetal literally means center seeking, so that should be toward the center of the circle.
00:23
The second part of the question says, by what factor would centripetal force change if the radius was cut in half? so what we're going to do is use this centripetal force equation and compare what f sub c would be if we cut the radius in half.
00:48
So we're going to let radius one be one unit, radius two we're going to let be one half unit, because we want the second radius to be half the first.
01:01
In the centripetal force equation we will fill in r one for r one, which would give us f sub c equals mv squared over one, or f sub c equals mv squared.
01:24
For radius two, if we cut it down to a half, we'd have f sub c equals mv squared over one half...