A roller coaster at an amusement park has a dip that bottoms out ina vertical circle of radius r. A passenger feels the seat of thecar pushing upward on her with a force equal to twice her weight asshe goes through the dip. If r = 20.0 m, how fast is the rollercoaster traveling at the bottom of the dip?
a. 9.89 m/s
b. 14.0 m/s
c. 20.2 m/s
d. 11.8 m/s
e. 18.1 m/s