1.Bicyclists in the Tour de France do enormous amounts of work during a race. For example, the average power per kilogram generated by Lance Armstrong (m = 75.0 kg) is 6.50 W per kilogram of his body mass. (a) How much work does he do during a 126-km race in which his average speed is 12.4 m/s? (b) Often, the work done is expressed in nutritional Calories rather than in joules. Express the work done in part (a) in terms of nutritional Calories, noting that 1 joule = 2.389 x 10^-4 nutritional Calories

2.A helicopter, starting from rest, accelerates straight up from the roof of a hospital. The lifting force does work in raising the helicopter. An 840-kg helicopter rises from rest to a speed of 7.5 m/s in a time of 3.0 s. During this time it climbs to a height of 8.8 m. What is the average power generated by the lifting force