1. The problem statement, all variables and given/known data Cyclist pedals downward stroke with 80N of energy. The diameter of the circle traced by his pedals is 36 cm, how much work is done each stroke? 2. Relevant equations W=F•d 3. The attempt at a solution I figured that the force exerted downwards means half of the circle traced, which would mean that it would be 80 N per 18 centimetres. It was not so. does centripetal stuff have anything to do with this?