Question

A sleeping 68 kg man has a metabolic power of 65 w . you may want to review ( pages 323 - 327) . part a how many calories does he burn during an 8.0 hour sleep

Answer 1

Given:

Mass = 68 kg

Power = 65 W

To determine:

Calories burned during an 8.0 hr sleep

Explanation:

Energy is expressed as:

Energy = Power * Time

Now, the unit of power = Watt (W)

1 W = 1 J/s i.e. 65 W = 65 J/s

Time = 8 hrs = 8 * 3600 s = 28800 s

Energy = 65 J/s * 28800 s = 1872000 J

Convert Joules (J) to calories (cal)

1 cal = 4.184 J

The calculated energy = 187200 J * 1 cal/4.184 = 447418 cal

Ans: The man burns nearly 447.4 kcal during an 8 hr sleep