Q. A BMX rider is about to ride over a large bump of radius R. What is the maximum speed the rider can travel without leaving the ground? Choice A. g/R B. gR C. (gR)^0.5 D. It depends on the mass of the rider The answer provided is C, but howcome g, gravity, is the centripedal acceleration? I was able to obtain the answer C by using this (V^2)/R = g = centripedal accel (C.A.). However, shouldn't the direction of the C.A. be perpendicular to the direction the rider is moving to? g is in fact the C.A. at the top of the large bump, but when the rider is going up or coming down, I don't think g is the C.A. Am I not correct? Thank you and Happy New Year!