Question

Bicyclists in the Tour de France do enormous amounts of work during a race. For example, the average power per kilogram generated by seven-time-winner 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 145-km race in which his average speed is 13.5 m/s?
Express answer in joules

(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 10-4 nutritional Calories.
Express answer in nurtitional calories.

Answer 1

Work= •m•t= P•m•s/v =6.5•75•145000/13.5=5.23•10⁶J =1.25 nutr.Cal.

Answer 2

Work=P •m•t= P•m•s/v =6.5•75•145000/13.5=5.23•10⁶J =1.25 nutr.Cal.

Answer 3

Work=P •m•t= P•m•s/v= =6.5•75•145000/13.5=5.23•10⁶J =
= 1.25•10³ nutr.Cal.
Now it's OK