Fish control their buoyancy through the use of a swim bladder, a gas-filled organ inside the body. You can assume that the pressure inside the swim bladder is roughly equal to the external water pressure. A fish swimming at a particular depth adjusts the volume of its swim bladder to give it neutral buoyancy. If the fish swims upwards or downwards, the changing water pressure causes the bladder to expand or contract. Consequently, the fish adjusts the amount of gas in the bladder to restore it to the original volume and reestablish neutral buoyancy. Consider a large, 10.0 kg striped bass swimming in fresh water. When neutrally buoyant, 7% of the total volume of the fish is taken up by air in the swim bladder. Assume a constant body temperature of 15°C and neglect the mass of the air in your calculations. If the fish begins at a depth of 20 meters, what will the volume of the swim bladder be if the fish ascends to a depth of 10 m without changing the quantity of gas in the swim bladder?

The tympanic membrane, or eardrum, is a structure that separates the external and middle parts of the ear (see the figure). It is sensitive to and vibrates in response to changes in air pressure and transmits these vibrations to other structures in the inner ear that lead to the sensation of hearing. Under normal conditions, the pressure on the inside and outside of the tympanic membrane are kept approximately equal. The auditory tube, also called the Eustachian tube, is responsible for this equilibration. However, rapid changes in external pressure can cause large pressure differentials on the tympanic membrane, causing it to rupture. A differential force across the eardrum membrane as little as 5.0 N can cause a rupture. (a) If the cross-sectional area of the membrane is 1.0 cm², what is the maximum tolerable pressure difference between the external and inner ear? (b) Based on your answer in part (a), to what maximum depth could a person dive in fresh water before rupturing an…

A tall graduated cylinder contains 7 cm of oil (density of 825 kg/m3kg/m3) on top of 20 cm of water (density of 1000 kg/m3kg/m3). The cylinder is open to the air. What is the pressure in the water, 3 cm above the bottom of the cylinder? (in Pa)  1.0323×105  1.0335×105  1.0353×105  1.0294×105  1.0157×105

There is a maximum depth at which a diver can breathe through a snorkel tube because as the depth increases, so does the pressure difference, which tends to collapse the diver’s lungs. Since the snorkel connects the air in the lungs to the atmosphere at the surface, the pressure inside the lungs is atmospheric pressure. What is the external–internal pressure difference when the diver’s lungs are at a depth of 6.1 m (about 20 ft)? Assume that the diver is in freshwater. (A scuba diver breathing from compressed air tanks can operate at greater depths than can a snorkeler, since the pressure of the air inside the scuba diver’s lungs increases to match the external pressure of the water.)

Blood pressure is measured when the blood is pumping (systolic) and when the heart is resting (diastolic). When pressure readings are given, the systolic is given first, and healthy blood pressure is around 120 over 80 mm Hg. Recall the density of mercury is 13.6 × 103 kg/m3. a. Suppose you have a blood pressure reading of 116 over 82 mm Hg. What is your systolic pressure, in newtons per meter squared?  b. Suppose you have a blood pressure reading of 116 over 82 mm Hg. What is your diastolic pressure, in newtons per meter squared?

What is the force due to atmospheric pressure on the outside of a 0.5m × 0.25m window? N. Why doesn't this force break the window due to this force?

Smoking can cause a person's arteries to constrict to 90 % of their normal radius. If the usual pressure difference needed to maintain a healthy blood flow rate in an artery is 405 Pa, what new pressure difference is needed to maintain the same volume flow rate (NOT flow speed)? You may assume that the artery has a length of 10 cm, a radius of 2 mm, and that blood has a viscosity of 2.7×10−3N⋅s/m2.7×10−3N⋅s/m. (in Pa)  450  328  617  500  266

The figure below shows 5 containers of water. A and B have the same height, as do C and E. A and E have the same area on the bottom, as do B and C. D has the largest area and the lowest height. Rank the pressure at the bottom of each container, from least to most (least occurs first, most occurs last). A B E O D, A=B, C=E O C=B, A=E, D D, C, В, А, E С, В, А, Е, D D, A%-DB, С, E

The top of your head is about 30 cm above your heart. What is the blood pressure difference between your heart and the top of your head?

A 0.481 kg0.481 kg metal cylinder is placed inside the top of a plastic tube, the lower end of which is sealed off by an adjustable plunger. The cylinder comes to rest some distance above the plunger. The plastic tube has an inner radius of 5.54 mm5.54 mm and is frictionless. Neither the plunger nor the metal cylinder allow any air to flow around them. If the plunger is suddenly pushed upwards, increasing the pressure between the plunger and the metal cylinder by a factor of 2.792.79, what is the initial acceleration ?a of the metal cylinder? Assume the pressure outside of the tube is 1.00 atm1.00 atm and that the top of the tube is open to the air.