Your father and your younger brother are confronted with the same puzzle. Your father’s garden sprayer and your brother’s water cannon both have tanks with a capacity of 5.00 L (Fig. P18.18). Your father puts a negligible amount of concentrated fertilizer into his tank. They both pour in 4.00 L of water and seal up their tanks, so the tanks also contain air at atmospheric pressure. Next, each uses a hand-operated pump to inject more air until the absolute pressure in the tank reaches 2.40 atm. Now each uses his device to spray out water—not air—until the stream becomes feeble, which it does when the pressure in the tank reaches 1.20 atm. To accomplish spraying out all the water, each finds he must pump up the tank three times. Here is the puzzle: most of the water sprays out after the second pumping. The first and the third pumping-up processes seem just as difficult as the second but result in a much smaller amount of water coming out. Account for this phenomenon.
Figure P18.18
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- A vertical cylinder of cross-sectional area A is fitted with a tight-fitting, frictionless piston of mass m (Fig. P18.40). The piston is not restricted in its motion in any way and is supported by the gas at pressure P below it. Atmospheric pressure is P0. We wish to find the height h in Figure P18.40. (a) What analysis model is appropriate to describe the piston? (b) Write an appropriate force equation for the piston from this analysis model in terms of P, P0, m, A, and g. (c) Suppose n moles of an ideal gas are in the cylinder at a temperature of T. Substitute for P in your answer to part (b) to find the height h of the piston above the bottom of the cylinder. Figure P18.40arrow_forwardA vertical cylinder of cross-sectional area A is fitted with a tight-fitting, frictionless piston of mass m (Fig. P16.56). The piston is not restricted in its motion in any way and is supported by the gas at pressure P below it. Atmospheric pressure is P0. We wish to find die height h in Figure P16.56. (a) What analysis model is appropriate to describe the piston? (b) Write an appropriate force equation for the piston from this analysis model in terms of P, P0, m, A, and g. (c) Suppose n moles of an ideal gas are in the cylinder at a temperature of T. Substitute for P in your answer to part (b) to find the height h of the piston above the bottom of the cylinder.arrow_forwardYou have completed several dives using SCUBA apparatus and are ready for a deep dive in seawater. You have arranged to have tanks of heliox prepared for your dive. Heliox is a mixture of helium and oxygen. Oxygen at pressures much greater than 1 atm is toxic to lung cells, so you want to keep the partial pressure of oxygen from your diving equipment at 1 atm or less during your dive. You will be diving at a depth of h = 51.8 m. What ratio of helium to oxygen, by weight, should you request for the mixtures in your tanks? The partial pressure of a gas in a mixture is the pressure the gas would have if it existed by itself in the same volume. Dalton's law of partial pressures tells us that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases. (The density of seawater is 1,030 kg/m³. Assume the air pressure at sea level is 1 atm.) WHE W02arrow_forward
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- A 0.435 kg0.435 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 6.56 mm6.56 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.arrow_forwardA pressure versus volume (pV) diagram for a system is shown in the figure. The arrows of the curve indicate the direction of the process, and the points of interest are labeled. The values for the points in the diagram are shown in the table. Volume (m³) Pressure (Pa) 2 Vo = 27.8 po = 1.37 × 10ª Vi = 20.8 Pi = 1.37 × 104 V2 = 17.4 P2 = 6.18 × 10³ V3 = 13.9 P3 = 6.18 × 10³ V4 = 13.9 P4 = 2.64 x 103 Vs = 8.87 p5 = 1.00 x 10³ Volume (m) Calculate the amount of work done on the system from 0–2 (Wm) and then for the entire curve from 0-5 (Wos). Pressure (Pa)arrow_forwardA vertical piston–cylinder device contains a gas at a pressure of 100 kPa. The piston has a mass of 5 kg and a diameter of 12 cm. Pressure of the gas is to be increased by placing some weights on the piston. Determine the local atmospheric pressure and the mass of the weights that will double the pressure of the gas inside the cylinder.arrow_forward
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