So, this was one of a few questions I got given in a physics lesson (A2 level, if you're wondering) today- and it seems that it doesn't give you enough information to answer:

"If the combined mass of Dan and his bicycle is 1000kg [rather large, I know!] calculate the centripetal force if his turning circle has a radius of 3m".

So, as far as I can see, this question is unanswerable as it cannot be answered directly using

or by using a value for a time (as none was given), and working out linear velocity from there using

Any suggestions? Or is it unanswerable?