The heart pumps blood at an average rate of 5L/min. The gauge pressure on the venous (intake) side is 0mm Hg and that on the arterial (discharge) side is 100mm Hg. Energy is supplied to the heart as heat released bytheabsorptionof :5mL(STP)O2/minisabsorbed, and20.2Jis released per mLof O2 absorbed. Part of thisabsorbed energy isconverted to ow work (the work done to pump blood through the circulatory system), and the balance is lost as heat transferred to the tissues surrounding the heart. (a) Simplify Equation 7.4-12 for this system, assuming (among other things) that there is no change in internal energy from inlet to outlet. (b) What percentage of the heat input to the heart _ Qin is converted to ow work? (The answer may be thought of as the efciency of the heart as a pump.)