00:01
In this problem we have centripetal motion of a train and we want to find the minimum radius so that the passengers don't experience more than 0 .05 times graphic.
00:14
So let's find that remembering that centripetal acceleration is equal to the velocity squared over the radius.
00:24
So the radius is going to be equal to the velocity squared all over the acceleration, the centripetal.
00:31
Acceleration.
00:36
So we find that this radius is going to be a minimum.
00:45
So it could be greater than or equal to whatever we find over here.
00:54
Now let's use the velocity we have.
00:56
We were told that the train is traveling at 216 kilometers per hour.
01:07
But this is kilometers per hour and we need meters per second so that our units are compatible.
01:14
So let's let's convert this velocity by multiplying it by a thousand to convert it to meters and dividing it by 60 squared to convert it to per second.
01:30
And this is going to be equal to 60 meters per second.
01:35
Okay, so let's use that now...