The human heart pumps the average adult\'s 5.6L (5600 cm3 ) of blood through the
ID: 2180407 • Letter: T
Question
The human heart pumps the average adult's 5.6L (5600 cm3 ) of blood through the body every minute. The heart must do work to overcome frictional forces that resist blood flow. The average adult blood pressure is 1.2 times 104N/m2. Hint: When the heart contracts, it applies force to the blood. Pressure is force/area. Model the circulatory system as a single closed tube, with cross-section area A and volume V = 5.6L , filled with blood to which the heart applies a force. How much work does the heart do to move the 5.6L of blood completely through the body? Express your answer to two significant figures and include the appropriate units. What power output must the heart have to do this task once a minute? Express your answer to two significant figures and include the appropriate units.Explanation / Answer
Litres of blood pumped every minute = 5600cm3 = 5600 X (1m/100)3 = 56X10-4m3
Blood Pressure = 1.2 X 108N/m2
a) Work done = Blood Pressure X Litres of blood pumped every minute
W = 1.2 X 108 X 56 X 10-4 J = 67.2 X 104 J
b) Power required to do the work once a minute = 67.2 X 104J/60 secs = 1.12 X 104 W
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.