Bird bones have air pockets to reduce their weight—this also gives them an average density significantly less than that of the bones of other animals. Suppose an ornithologist weighs a bird bone air and in water and finds its mass is 45.0 g ad its apparent mass when submerged is 3.60 g (assume the bone is watertight.)(a) What mass of is displaced? (b) What is the volume of the bone? (c) What is its average density?

Water supplied to a house by a water main has a pressure of 3.00105N/m2 early on a summer day when neighborhood use is low. This pressure produces a flow of 20.0 L/min through a garden hose. Later in the day, pressure at the exit of the water main and entrance to the house drops, and a flow of only 8.00 L/min is obtained through the same hose. (a) What pressure is now being supplied to the house, assuming resistance is constant? (b) By what factor did the flow rate be water main increase in order to cause this decrease in delivered pressure? The pressure at the entrance of the water main is 5.00105N/m2 , and the original rate was 200 L/min. (c) How many more users are there, assuming each would consume 20.0 L/min in be morning?

An airplane is cruising al altitude 10 km. The pressure outside the craft is 0.287 atm; within the passenger compartment, the pressure is 1.00 atm and the temperature is 20C. A small leak occurs in one of the window seals in the passenger compartment. Model the air as an ideal fluid to estimate the speed of the airstream flowing through the leak.

How many cubic meters of helium are required to lift a balloon with a 400-kg payload to a height of 8 000 m? Take He = 0.179 kg/m3. Assume the balloon maintains a constant volume and the density of air decreases with the altitude z according to the expression air = 0ez/8, where z is in meters and 0 = 1.20 kg/m3 is the density of air at sea level.

A backyard swimming pool with a circular base of diameter 6.00 m is filled to depth 1.50 m. (a) Find the absolute pressure at the bottom of the pool. (b) Two persons with combined mass 150 kg enter the pool and float quietly there. No water overflows. Find the pressure increase at the bottom of the pool after they enter the pool and float.

-2. A sçuba diver breathes air from a tank which has a pressure regulator that automatically adjusts the pressure of the inhaled air to the ambient pres- sure. If a diver 40 m below the surface of a deep lake fills his lungs to the full capacity of 6 liters and thẹn rises quickly to the surface, to what vol- ume will his lungs expand? Is such a rapid ascent advisable?

Helium gas with a gauge pressure of 58 kPa is stored within a cube that has 45 cm long sides. Assuming that the cube is completely suspended in air with a pressure of 1 atm, what is the net force on each one of the faces of the cube?

When an automobile moves for a long time, the air pressure in tyres increases slightly. Why?

(b) An advertising blimp consists of a gas bag, the supporting structure for the gas bag, and the gondola hung from the bottom, with its cabin, engines, and propellers. The gas bag is about 25 m long with a diameter of about 13 m, and it is filled with helium (density about 4 g per 22.4 l under these conditions). Estimate the total mass of the blimp, including the helium. (Assume the blimp is in the shape of a cylinder, and that the density of air is 1.2 kg/m3.)