A standing wave can be created when a disturbance (wave) is trapped between two boundaries. Thus, standing sound wave can be produced when gas is confined in long narrow tube closed at both ends. In addition, standing waves can be produced in tubes with an opening at one end of the tube as well (open-closed tube). The eardrum can be modeled as an open-closed tube. The ear canal in adults is about 2.5 cm in length. Thus, what frequency ranges can occur in the ear canal that are within the range of human hearing? In other words, what is the fundamental frequency of the ear canal? The speed of sound in the warm air of the ear canal is 350 m/s. Hint: Wavelength of standing waves in open-closed tubes are given by the following: λ = 4L where m = 1,3,5,7 m

A cardiologist reports to her patient that he radius of the left anterior descending artery of the heart has narrowed by 10.0%. What is the percent increase in the blood pressure drop across the artery that is required to maintain the normal blood flow through artery? Hint: To main normal blood flow, the blood volume flow rate must remain the same (Qnormal = Qdecreased). Poiseuille's Law gives the equation for volume flow rate of a viscous fluid. Please review Chapter 11 and continuity equation.

The heart pumps blood into the aorta, which has an inner radius of 1.0 cm. The aorta feeds 32 major arteries. If the blood in the aorta travels at a speed of 28 cm/s, at approximately what average speed in units of m/s does it travel in the arteries? Assume that blood can be treated as an ideal fluid and that the arteries each have an inner radius of 0.21 cm.