Chapter 6, Problem 6.9E

HW12 A multiple-disc clutch has five plates having four pairs of active friction surfaces. If the intensity of pressure is not to exceed 0.127 N/mm², find the power transmitted at 500 r.p.m. The outer and inner radii of friction surfaces are 125 mm and 75 mm respectively. Assume uniform wear and take the coefficient of friction = 0.3.

The sketch below gives some details of the human heart at rest. What is the total power requirement (work/time) for an artificial heart pump if we use a safety factor of 5 to allow for inefficiencies, the need to operate the heart under stress, etc.? Assume blood has the properties of water. p pressure above atmosphere blood going to the lungs for a fresh charge of oxygen p = 2.9 kPa 25v pulmonary artery d = 25mm fresh oxygenated blood from the lungs p = 1.0 kPa vena cava d=30mm right auricle pulmonary vein, d = 28mm aorta, d=20mm spent blood returning from left auricle the body p = 0.66 kPa right left ventricle ventricle blood to feed the body, p 13 kPa normal blood flow = 90 ml/s

4- A horizontal Venturi meter is used to measure the flow rate of water through the piping system of 20 cm I.D, where the diameter of throat in the meter is d₂ = 10 cm. The pressure at inlet is 17.658 N/cm2 gauge and the vacuum pressure of 35 cm Hg at throat. Find the discharge of water. Take Cd = 0.98.