How Much Work Does the Human Heart Perform in a Day?

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SUMMARY

The human heart pumps approximately 7,500 liters of blood daily, equating to a volume of 7,500,000 cubic meters. To calculate the work done by the heart, the appropriate formula is W = mgh, where 'm' is the mass of the blood, 'g' is the acceleration due to gravity, and 'h' is the height. The power output can be determined using P = W/t, converting the result to horsepower for clarity. The discussion highlights the importance of using potential energy calculations over kinetic energy for this specific scenario.

PREREQUISITES
  • Understanding of basic physics concepts such as work, power, and energy.
  • Familiarity with the formula W = mgh for calculating potential energy.
  • Knowledge of unit conversions, particularly between liters and cubic meters.
  • Basic understanding of horsepower and its conversion from watts.
NEXT STEPS
  • Research the principles of potential energy and its applications in biological systems.
  • Study the relationship between work and power in mechanical systems.
  • Explore unit conversions between metric and imperial systems, focusing on fluid volumes.
  • Learn about the physiological implications of heart performance metrics in health sciences.
USEFUL FOR

Students in physics or biology, healthcare professionals interested in cardiovascular health, and anyone studying human physiology or mechanics of the heart.

Ogakor
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Homework Statement


The human heart is a powerful and extremely reliable pump. Each day, it takes in and discharges about 7,500 liters or blood. If the work done by the heart is that of an average American female, 1.63m; and if the density of blood is 1.03 x 103 kg/cubic meter,
a) How much work does the heart do in a day?
b) What is its power output in watts and its horsepower?

given:
vol = 7,500 liters x (1000ml / 1 liter) x (1cubic meter / 1 liter) = 7,500,000 cubic meter
h = 1.63 m
p = 1.03 x 103 kg/cubic meter
t = 24 hourse = 86,400 s

a. So, in solving for work, my friend and I were arguing on what formula to use. He said, we should use W = mgh (potential energy) since everything is given. I said, we should use W = 1/2mv2 (kinetic energy). velocity can be solved with height / time. I wanted to use kinetic energy because this is moving energy. Both giving different results.
So, what should we use, the formula for kinetic energy or potential energy?

b. obviously, when work is solved, just use P = W/t and convert it to horse power. Am I correct? I only want to verify, please answer.
 
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