Take the density of blood to be and the distance between

Chapter 9, Problem 9.72

(choose chapter or problem)

Take the density of blood to be and the distance between the feet and the heart to be hH. Ignore the ow of blood. (a) Show that the difference in blood pressure between the feet and the heart is given by PF PH ghH. (b) Take the density of blood to be 1.05 103 kg/m3 and the distance between the heart and the feet to be 1.20 m. Find the difference in blood pressure between these two points. This problem indicates that pumping blood from the extremities is very difcult for the heart. The veins in the legs have valves in them that open when blood is pumped toward the heart and close when blood ows away from the heart. Also, pumping action produced by physical activities such as walking and breathing assists the heart.