When lying down,the gauge pressure of the blood at a patient's heart is 13.3 kPa.If the patient suddenly stands up and her body doesn't compensate quickly enough for the pressure changes,what would be the pressure at her head,55.0 cm above her heart? The density of blood is 1 060 kg/m³.

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Quizplus · Accepted Answer

The pressure at the patient's head when they stand up can be calculated using the hydrostatic pressure formula: $P = P_0 + \rho gh$, where $P_0$ is the initial pressure (13.3 kPa or 13300 Pa), $\rho$ is the density of blood (1060 kg/m³), $g$ is the acceleration due to gravity (9.8 m/s²), and $h$ is the height difference (0.55 m). The pressure difference due to the height change is $\Delta P = \rho gh = 1060 \times 9.8 \times 0.55$, which calculates to approximately 5703 Pa. Subtracting this from the initial pressure gives the pressure at the head: $13300 - 5703 = 7597$ Pa, or $7.59 \times 10^3$ Pa.

When Lying Down,the Gauge Pressure of the Blood at a Patient's