In physics 1 courses this problem comes set up without velocity, e.g. a snowboarder of mass M drops from rest into a halfpipe of radius R. Your only two knowns are the radius and the mass; you need to find the snowboarder's velocity at the bottom of the pipe. You handwaved that part.
When calculating your Centripetal Acceleration, shouldn't it have been Velocity sq over a radius of 5, rather than 6?
In physics 1 courses this problem comes set up without velocity, e.g. a snowboarder of mass M drops from rest into a halfpipe of radius R. Your only two knowns are the radius and the mass; you need to find the snowboarder's velocity at the bottom of the pipe. You handwaved that part.