Question

Aa particular bicycle is 25% effificent in converting the energy of a cyclist to mechanical energy (that is, she puts in four times as much energy as she gets out). if a cyclist is travelling along a pathway at a constant speed of 5.8 m/s for 1 h, and the aveage resistance is 22 N, how much mass does she lose assuming 1 kg is lost for each 2.9 x 10^7 J of energy she uses?