A cyclist pedals a long slope which is at 5.0° to the horizontal. The cyclist starts from rest at the top of the slope and reaches a speed of 12 m/s after a time of 67s, having travelled 40 m down the slope. The total mass of the cyclist and bicycle is 90 kg.

a. Calculate:

i. the loss in gravitational potential energy as he travels down the slope ii. the increase in kinetic energy as he travels down the slope.

b. i. Use your answers to a to determine the useful power output of the cyclist.
ii. Suggest one reason why the actual power output of the cyclist is larger than your value in i.