Power can be expressed as the product of force applied and velocity (a) Prove this expression, starting from the definition of power. (b) A cyclist is pedalling along a horizontal road provides 200W of useful power, reaching a steady speed of 5.0 ms 1. What is the value of the drag force against which the cyclist is working? (e) The drag force is proportional to the speed of the the bicycle. Predict what power the cyclist must produce reach a speed of 6.0 ms ' along the flat, given that the useful power the cyclist must produce at speed v is proportional to v2 (d) What useful power would the cyclist have to develop to maintain a speed of 5.0 ms-when climbing a hill that rises Im for every 5m forwards. The cyclist and bike have a combines mass of H5kg