Question

Under normal conditions the human heart converts about 12.5J of chemical energy per second into 1.25 W of mechanical power as it pumps blood throughout the body. (a) Determine the number of Calories required to power the heart for one day, given that 1 Calorie equals 4186 J. ________ Cal (b) Metabolizing 1 kg of fat can release about 9000 Calories of energy. What mass of metabolized fat (in kg) would power the heart for one day? _____ kg

Answer 1

(a) The number of Calories required to power the heart for one day is 258 Cal.

(b) The mass of metabolized fat that would power the heart for one day is 0.0287 kg.

What is the number of Calories required to power the heart?

The number of Joules of energy required to power the heart for one day is calculated as follows;

Power = 12.5 J / s

Energy = power x time

time = 1 day = 86400 seconds

Energy pumped by heart in one day = 12.5 J/s  x 86400 s = 1,080,000 J

The number of calories contained in 1,080,000 J of chemical energy is calculated as;

1 Calorie = 4186 J

= 1,080,000 J / 4186 J

= 258 Cal

The mass of metabolized fat that would power the heart for one day is calculated as;

9000 Cal = 1 kg

258 Cal = ?

= 258 / 9000

= 0.0287 kg

Learn more about energy in calories here: https://brainly.com/question/28589779

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