Posted by Anonymous on .
A roller coaster at an amusement park has a dip that bottoms out in a vertical circle of radius r. A passenger feels the seat of the car pushing upward on her with a force equal to twice her weight as she goes through the dip. If r = 19.0 m, how fast is the roller coaster traveling at the bottom of the dip?

college physics 
macky so,
that's an interesting question. Let me ask my professor, and I'll get back to you.