1. The problem statement, all variables and given/known data A cyclist riding a bicycle finds that he needs to pedal harder in order to travel faster. The main reason for this is that: A the friction between the tyres and the road decreases with speed. B there is greater air resistance at higher speeds. C the bike has more inertia at high speed. D the cyclist exerts a greater force to oppose the motion of the pedals. 2. Relevant equations None 3. The attempt at a solution I chose D because to pedal faster means greater force on the pedals but I am not sure.