Calculating Volume from Flow Rate: The Heart Pumps a Lot of Blood in a Lifetime

How many cubic meters of blood does the heart pump in a 75-year lifetime, assuming the average flow rate is 5.00 L/min?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Strategy
Time and flow rate $Q$ are given, and so the volume $V$ can be calculated from the definition of flow rate.
Solution
Solving $Q = V / t$ for volume gives

$V = Qt .$
12.2

Substituting known values yields

$\begin{array}{l} V & = & (\frac{5.00 L}{1 min}) (75 y) (\frac{1 m^{3}}{10^{3} L}) (5 . 26 \times 10^{5} \frac{min}{y}) \\ = & 2 . 0 \times 10^{5} m^{3} . \end{array}$
12.3
Discussion
This amount is about 200,000 tons of blood. For comparison, this value is equivalent to about 200 times the volume of water contained in a 6-lane 50-m lap pool.

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