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
Want to see the full answer?
Check out a sample textbook solutionChapter 19 Solutions
Physics for Scientists and Engineers, Technology Update (No access codes included)
- 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_forwardA student is asked to sketch a pV diagram for a gas that goes through a cycle consisting of (a) an isobaric expansion, (b) a constant-volume reduction intemperature, and (c) an isothermal process that returns the gas to its initial state. The student draws the diagram as shown. What, if anything, is wrong with the student’s diagram?arrow_forward
- You 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_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 = 41.8 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 = 0.77 Wo2 Find the ratio of numbers of molecules for the two gases first, demanding that the oxygen…arrow_forwardIn the lungs, the respiratory membrane separates tiny sacs of air (absolute pressure=1.00x105 Pa) from the blood in the capillaries. These sacs are called alveoli, and it is from them that oxygen enters the blood. The average radius of the alveoli is 0.125 mm, and the air inside contains 14% oxygen, which is somewhat smaller amount than in fresh air. Assuming that the air behaves as an ideal gas at body temperature (310 K), find the number of oxygen molecules in one of the sacs.arrow_forward
- A high-pressure gas cylinder contains 50.0 L of toxic gas at a pressure of 1.25 × 107 Pa and a temperature of 25.0°C. Its valve leaks after the cylinder is dropped. The cylinder is cooled to dry ice temperature (-78.5°C) to reduce the leak rate and pressure so that it can be safely repaired. a.) What is the final pressure, in pascals, in the tank, assuming a negligible amount of gas leaks while being cooled and that there is no phase change? b.) What is the final pressure, in pascals, if 1/10 of the gas escapes during this process? c.) To what temperature, in kelvins, must the tank be cooled from its initial state to reduce the pressure to 1.00 atm (assuming the gas does not change phase and there is no leakage during cooling)?arrow_forwardThe plunger of a syringe has an internal diameter of 1.0 cm and the end of the needle has an internal diameter of 0.35 mm. A practitioner lightly squeezes the plunger, but no serum is emitted by the needle into a vein. So the practitioner gradually increases the squeezing force that she exerts on the plunger such that serum begins to be emitted from the needle into the vein. Assuming no surface tension or friction, what is the minimum squeezing force that the practitioner applies to the plunger in order that serum begins to be emitted from the needle into the vein? Take the pressure of blood in the vein to be 20 mmHg above that of atmospheric pressure. 0.70 N 3.3 N 0.21 N 0.24 N 1.4 N 17Narrow_forwardA blocked bicycle pump contains 0.682 L air at 99.3 kPa. If the handle is pressed down, decreasing the volume of the inside air to 0.151 L, what is the pressure inside the pump? Assume that the temperature of the air does not change.arrow_forward
- A 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) v0=27.4 p0=1.00×104 v1=19.3 p1=1.00×104 v2=16.0 p2=4.92×103 v3=13.3 p3=4.92×103 v4=13.3 p4=3.20×103 v5=7.51 p5=1.00×103 Calculate the amount of work done on the system from 0–2 (W02) and then for the entire curve from 0–5 (W05).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 cylinder containing ideal gas is sealed by a piston that is above the gas. The piston is a cylindrical object, with a weight of 22.0 N, which can slide up or down in the cylinder without friction. The inner radius of the cylinder, and the radius of the piston, is 8.00 cm. The top of the piston is exposed to the atmosphere, and the atmospheric pressure is 101.3 kPa. The cylinder has a height of 30.0 cm, and, when the temperature of the gas is 20°C, the bottom of the piston is 11.0 cm above the bottom of the cylinder. (A) Find the number of moles of ideal gas in the cylinder. (B) Heat is added, gradually raising the temperature of the gas to 160°C. Calculate the distance between the bottom of the cylinder and the bottom of the piston when the piston comes to its new equilibrium position.arrow_forward
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning