00:01
Okay, so we have a roller coaster going over a circular track, and we're told that the radius here is 14 meters, and we're told that the velocity at the top is 11 meters per second, and we want to know what the force from the track on the cart is.
00:36
So we have our cart here at this time.
00:39
And there are two forces acting here.
00:41
We have the normal force and m .g.
00:49
Acting downward.
00:50
And because this is circular motion, our acceleration is centripetal acceleration.
00:58
And when they're at the very top, it's acting downward.
01:02
So we also are given the mass of the cart here.
01:08
That's 1 ,040 kilograms.
01:11
So we know that the net force or the sum of the forces here has equal mass times acceleration.
01:21
And our acceleration here is the centripetal acceleration, which is also given by v squared over r.
01:28
Or r is the radius.
01:30
So we can set the forces acting here equal to mv squared over r...