Question

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 164-km race in which his average speed is 11.1 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.

Answer 1

Answer:

1720.725 Calories

Explanation:

Time = Distance / Speed

$Time=\frac{164000}{11.1}=14774.77\ s$

Work done

$W=Ptm\\\Rightarrow W=6.5\times 14774.77\times 75\\\Rightarrow W=7202700.375\ J$

Converting to calories

$1\ Joule=2.389\times 10^{-4}\ Calories$

$7202700.375\ Joule=7202700.375\times 2.389\times 10^{-4}\ Calories=1720.725\ Calories$

The work done is 1720.725 Calories