Conceptual Physics 11th edition Paul G. Hewitt - Solutions

Discover comprehensive solutions and answers key for "Conceptual Physics 11th Edition" by Paul G. Hewitt. Access the complete solution manual and solved problems to enhance your understanding of the textbook. Our online platform offers a free download of step-by-step answers and chapter solutions, making it an essential resource for students and instructors alike. Whether you're preparing for exams with the test bank or seeking an instructor manual, our solutions PDF ensures you have all the questions and answers you need at your fingertips.

A space heating unit in Alaska uses propane combustion is the heat supply. Liquid propane comes from an outside tank at -44°C and the air supply is also taken in from the outside at -44°C. The airflow regulator is misadjusted, such that only 90% of the theoretical air enters the combustion
Consider the following coal gasifier proposed for supplying a syngas fuel to a gas turbine power plant. Fifty kilograms per second of dry coal (represented as 48 kg C plus 2 kg H) enter the gasifier, along with 4.76 kmol/s of air and 2 kmol/s of steam. The output stream from this unit is a gas
One kilomole of liquid oxygen, O2, at 93 K, and x kmol of gaseous hydrogen, H2, at 25°C, are fed to a combustion chamber. x is greater than 2, such that there is excess hydrogen for the combustion process. There is a heat loss from the chamber of 1000 kJ per kmol of reactants. Products exit the
Saturated liquid butane (note: use generalized charts) enters an insulated constant pressure combustion chamber at 25°C, and x times theoretical oxygen gas enters at the same pressure and temperature. The combustion products exit at 3400 K. Assuming that the products are a chemical equilibrium gas
Derive the van’t Hoff equation given in problem 15.48, using Eqs.15.12 and 15.15. Note: the d(g-/T) at constant P for each component can be expressed using the relations in Eqs. 13.18 and 13.19.
A coal gasifier produces a mixture of 1 CO and 2H2 that is then fed to a catalytic converter to produce methane. A chemical-equilibrium gas mixture containing CH4, CO, H2, and H2O exits the reactor at 600 K, 600 kPa. Determine the mole fraction of methane in the mixture.
Dry air is heated from 25°C to 4000 K in a 100-kPa constant-pressure process. List the possible reactions that may take place and determine the equilibrium composition. Find the required heat transfer.
Methane is burned with theoretical oxygen in a steady flow process, and the products exit the combustion chamber at 3200 K, 700 kPa. Calculate the equilibrium composition at this state, assuming that only CO2, CO, H2O, H2, O2, and OH are present. Combustion: CH4 + 2 O2 → CO2 + 2 H2O
At 298 K, K = exp (-184) for the water dissociation, what does that imply?
Is stagnation temperature always higher than free stream temperature? Why?
To maximize the mass flow rate of air through a given nozzle, which properties should I try to change and in which direction, higher or lower?
Can any low enough backup pressure generate an isentropic supersonic flow?
Is there any benefit to operate a nozzle choked?
To increase the flow through a choked nozzle, the flow can be heated/cooled or compressed/expanded (four processes) before or after the nozzle. Explain which of these eight possibilities will help and which will not.
Which of the cases in Fig. 16.17 (a-h) have entropy generation and which do not?
A given convergent nozzle operates so it is choked with stagnation inlet flow properties of 400 kPa, 400 K.To increase the flow, a reversible adiabatic compressor is added before the nozzle to increase the stagnation flow pressure to 500 kPa. What happens to the flow rate?
How much entropy per kg flow is generated in the shock in Example 16.9?
Which temperature does a thermometer or thermocouple measure? Would you ever need to make a correction to that?
How high can a gas velocity (Mach number) be and still treat it as incompressible flow within 2% error?
Steam leaves a nozzle with a pressure of 500 kPa, a temperature of 350°C, and a velocity of 250m/s. What is the isentropic stagnation pressure and temperature?
An object from space enters the earth’s upper atmosphere at 5 kPa, 100 K, with a relative velocity of 2000 m/s or more . Estimate the object's surface temperature.
Steam is flowing to a nozzle with a pressure of 400 kPa. The stagnation pressure and temperature are measured to be 600 kPa and 350°C, respectively. What are the flow velocity and temperature?
The products of combustion of a jet engine leave the engine with a velocity relative to the plane of 400 m/s, a temperature of 480°C, and a pressure of 75 kPa. Assuming that k = 1.32, Cp = 1.15 kJ/kg K for the products, determine the stagnation pressure and temperature of the products relative to
A meteorite melts and bum up at temperatures of 3000 K. If it hits air at 5 kPa, 50 K how high a velocity should it have to experience such a temperature?
I drive down the highway at110 km/h on a day with 25°C, 101.3 kPa. I put my hand, cross sectional area 0.01 m2, flat out the window. What is the force on my hand and what temperature do I feel?
Air leaves a compressor in a pipe with a stagnation temperature and pressure of 150°C, 300 kPa, and a velocity of 125 m/s. The pipe has a cross-sectional area of 0.02 m2. Determine the static temperature and pressure and the mass flow rate.
A stagnation pressure of 108 kPa is measured for an airflow where the pressure is 100 kPa and 20°C in the approach flow. What is the incoming velocity?
A jet engine receives a flow of 150 m/s air at 75 kPa, 5°C across an area of 0.6 m2 with an exit flow at 450 m/s, 75 kPa, 600 K. Find the mass flow rate and thrust.
The jet engine thrust is found from the overall momentum equation. Where is the actual force acting (it is not a long-range force in the flow)?
A 4-cm inner diameter pipe has an inlet flow of10 kg/s water at 20oC, 200 kPa. After a 90 degree bend as shown in Fig. P16.30, the exit flow is at 20°C, 190 kPa. Neglect gravitational effects and find the anchoring forces Fx and Fy.
A water cannon sprays 1 kg/s liquid water at a velocity of100m/s horizontally out from a nozzle. It is driven by a pump that receives the water from a tank at 15°C, 100 kPa. Neglect elevation differences and the kinetic energy of the water flow in the pump and hose to the nozzle. Find the nozzle
An irrigation pump takes water from a lake and discharges it through a nozzle as shown in Fig. P16.32. At the pump exit the pressure is 700 kPa, and the temperature is 20°C. The nozzle is located 10 m above the pump and the atmospheric pressure is 100 kPa. Assuming reversible flow through the
A jet engine at take off has air at 20oC, 100 kPa coming at 25 m/s through the 1.0 m diameter inlet. The exit flow is at 1200 K, 100 kPa, through the exit nozzle of 0.4 m diameter. Neglect the fuel flow rate and find the net force (thrust) on the engine.
A water turbine using nozzles is located at the bottom of Hoover Dam 175 m below the surface of Lake Mead. The water enters the nozzles at a stagnation pressure corresponding to the column of water above it minus 20% due to losses. The temperature is 15°C and the water leaves at standard
A water tower on a farm holds 1 m3 liquid water at 20°C, 100 kPa in a tank on top ofa5m tall tower. A pipe leads to the ground level with a tap that can open a1.5 cm diameter hole. Neglect friction and pipe losses, and estimate the time it will take to empty the tank for water.
Find the expression for the anchoring force Rx for an incompressible flow like in Figure 16.6. Show that it can be written as
Find the speed of sound for air at 100 kPa at the two temperatures 0°C and 30°C. Repeat the answer for carbon dioxide and argon gases.
If the sound of thunder is heard 5 seconds after the lightning is seen and the weather is 20°C. How far away is the lightning taking place?
Estimate the speed of sound for steam directly from Eq. 16.25 and the steam tables for a state of 6 MPa, 400°C. Use table values at 5 and 7 MPa at the same entropy as the wanted state. Eq. 16.25 is then done by finite difference. Find also the answer for the speed of sound assuming steam is an
How large a force must be applied to a squirt gun to have 0.1 kg/s water flow out at 20 m/s? What pressure inside the chamber is needed?
The speed of sound in liquid water at 250C is about 1500 m/s. Find the stagnation pressure and temperature for a M=0.1 flow at 25°C, 100 kPa. Is it possible to get a significant mach number flow of liquid water?
A convergent nozzle has a minimum area ofO.1 m and receives air at175 kPa, 1000 K flowing with 1OOm/s. What is the back pressure that will produce the maximum flow rate and find that flow rate?
A convergent-divergent nozzle has a throat area of 100 mm2 and an exit area of 175 mm2. The inlet flow is helium at a stagnation pressure of 1 MPa, stagnation temperature of375K. What is the back pressure that will give sonic condition at the throat, but subsonic everywhere else?
A jet plane travels through the air with a speed of 1000 km/h at an altitude of 6 km, where the pressure is 40 kPa and the temperature is -12°C. Consider the inlet diffuser of the engine where air leaves with a velocity of 100 m/s. Determine the pressure and temperature leaving the diffuser, and
Air is expanded in a nozzle from a stagnation state of 2 MPa, 600 Ktoa backpressure of1.9 MPa. If the exit cross-sectional area is 0.003 m , find the mass flow rate.
Air flows into a convergent-divergent nozzle with an exit area of1.59 times the throat area of 0.005 m. The inlet stagnation state is 1 MPa, 600 K. Find the backpressure that will cause subsonic flow throughout the entire nozzle with M = 1 at the throat. What is the mass flow rate?
Air flows into a convergent-divergent nozzle with an exit area of2.0 times the throat area of 0.005 m2. The inlet stagnation state is 1 MPa, 600 K. Find the backpressure that will cause a reversible supersonic exit flow with M=1at the throat. What is the mass flow rate?
Air is expanded in a nozzle from a stagnation state of 2 MPa, 600 K, to a static pressure of 200 kPa. The mass flow rate through the nozzle is 5 kg/s. Assume the flow is reversible and adiabatic and determine the throat and exit areas for the nozzle.
Air at150 kPa, 290 K expands to the atmosphere at 100 kPa through a convergent nozzle with exit area of 0.01 m2. Assume an ideal nozzle. What is the percent error in mass flow rate if the flow is assumed incompressible?
A convergent-divergent nozzle has a throat diameter of 0.05 m and an exit diameter of0.1 m. The inlet stagnation state is 500 kPa, 500 K. Find the back pressure that will lead to the maximum possible flow rate and the mass flow rate for three different gases as: air; hydrogen or carbon dioxide.
By looking at Eq. 16.25, rank the speed of sound for a solid, a liquid, and a gas. Speed of sound: (∂P/∂P)s = c2
A nozzle is designed assuming reversible adiabatic flow with an exit Mach number of2.6 while flowing air with a stagnation pressure and temperature of 2 MPa and 150°C, respectively. The mass flow rate is 5 kg/s, and k may be assumed to be 1.40 and constant. Determine the exit pressure,
A 1-m3 insulated tank contains air at 1 MPa, 560 K. The tank is now discharged through a small convergent nozzle to the atmosphere at 100 kPa. The nozzle has an exit area of2 x 10-5 m2. a. Find the initial mass flow rate out of the tank. b. Find the mass flow rate when half the mass has been
Assume the same tank and conditions as in Problem 16.51. After some flow out the nozzle flow changes to become subsonic. Find the mass in the tank and the mass flow rate out at that instant.
A 1-m3 uninsulated tank contains air at 1 MPa, 560 K. The tank is now discharged through a small convergent nozzle to the atmosphere at 100 kPa while heat transfer from some source keeps the air temperature in the tank at 560 K. The nozzle has an exit area of2 x 10-5 m2. Find the mass flow rate
Assume the same tank and conditions as in Problem 16.53. After some flow out the nozzle flow changes to become subsonic. Find the mass in the tank and the mass flow rate out at that instant.
The products of combustion enter a convergent nozzle of ajet engine at a total pressure of 125 kPa, and a total temperature of 650°C. The atmospheric pressure is 45 kPa and the flow is adiabatic, with a rate of 25 kg/s. Determine the exit area of the nozzle.
Consider the nozzle of Problem 16.47 and determine what back pressure will cause a normal shock to stand in the exit plane of the nozzle. This is case g in Fig. 16.17. What is the mass flow rate under these conditions?
At what Mach number will the normal shock occur in the nozzle of Problem 16.49 flowing with air if the back pressure is halfway between the pressures at c and d in Fig. 16.17?
The nozzle in Problem 16.50 will have a throat area of 0.001272 m and an exit area 2.896 times as large. Suppose the back pressure is raised to 1.4 MPa and that the flow remains isentropic except for a normal shock wave. Verify that the shock mach number (Mx) is close to 2 and find the exit mach
Consider the diffuser of a supersonic aircraft flying atM = 1.4at such an altitude that the temperature is -20°C, and the atmospheric pressure is 50 kPa. Consider two possible ways in which the diffuser might operate, and for each case calculate the throat area required for a flow of 50 kg/s. a.
Does speed of sound in an ideal gas depend on pressure? What about a real gas?
Consider the nozzle in problem 16.42 flowing air. What should the backpressure be for a normal shock to stand at the exit plane? This is case g in Fig.16.17. What is the exit velocity after the shock?
Air is expanded in a nozzle from 700 kPa, 200°C, to 150 kPa in a nozzle having an efficiency of 90%. The mass flow rate is 4 kg/s. Determine the exit area of the nozzle, the exit velocity, and the increase of entropy per kilogram of air. Compare these results with those of a reversible adiabatic
Repeat Problem 16.43 assuming a diffuser efficiency of80%.
Air enters a diffuser with a velocity of 200 m/s, a static pressure of70 kPa, and a temperature of-6°C. The velocity leaving the diffuser is 60 m/s and the static pressure at the diffuser exit is 80 kPa. Determine the static temperature at the diffuser exit and the diffuser efficiency. Compare the
Steam at a pressure of 1 MPa and temperature of 400°C expands in a nozzle to a pressure of 200 kPa. The nozzle efficiency is 90% and the mass flow rate is10 kg/s. Determine the nozzle exit area and the exit velocity.
A sharp-edged orifice is used to measure the flow of air in a pipe. The pipe diameter is 100 mm and the diameter of the orifice is 25 mm. Upstream of the orifice, the absolute pressure is 150 kPa and the temperature is 35°C. The pressure drop across the orifice is15 kPa, and the coefficient of
A critical nozzle is used for the accurate measurement of the flow rate of air. Exhaust from a car engine is diluted with air so its temperature is 50°C at a total pressure of 100 kPa. It flows through the nozzle with throat area of 700 mm2 by suction from a blower. Find the needed suction
Steam at 800 kPa, 350°C flows through a convergent-divergent nozzle that has a throat area of350 mm2. The pressure at the exit plane is 150 kPa and the exit velocity is 800 m/s. The flow from the nozzle entrance to the throat is reversible and adiabatic. Determine the exit area of the nozzle, the
Steam at 600 kPa, 300°C is fed to a set of convergent nozzles in a steam turbine. The total nozzle exit area is 0.005 m2 and they have a discharge coefficient of 0.94. The mass flow rate should be estimated from the measurement of the pressure drop across the nozzles, which is measured to be 200
A convergent nozzle is used to measure the flow of air to an engine. The atmosphere is at 100 kPa, 25°C. The nozzle used has a minimum area of 2000 mm2 and the coefficient of discharge is0.95.A pressure difference across the nozzle is measured to 2.5 kPa. Find the mass flow rate assuming
Can a convergent adiabatic nozzle produce a supersonic flow?
The coefficient of discharge of a sharp-edged orifice is determined at one set of conditions by use of an accurately calibrated gas meter. The orifice has a diameter of 20 mm and the pipe diameter is50 mm. The absolute upstream pressure is 200 kPa and the pressure drop across the orifice is 82 mm
A convergent nozzle with exit diameter of 2 cm has an air inlet flow of 20°C, 101 kPa (stagnation conditions). The nozzle has an isentropic efficiency of 95% and the pressure drop is measured to 50 cm water column. Find the mass flow rate assuming compressible adiabatic flow. Repeat calculation
At what Mach number will the normal shock occur in the nozzle of Problem 16.47 if the back pressure is 1.4 MPa? (trial and error on Mx)
Atmospheric air is at 20°C, 100 kPa with zero velocity. An adiabatic reversible compressor takes atmospheric air in through a pipe with cross-sectional area of 0.1 m2 at a rate of 1 kg/s. It is compressed up to a measured stagnation pressure of 500 kPa and leaves through a pipe with
Sketch the variation in V, T, P, p and M for a subsonic flow into a convergent nozzle with M =1at the exit plane?
Sketch the variation in V, T, P, p and M for a sonic (M =1) flow into a divergent nozzle with M =2at the exit plane?
In a meeting room, there are chairs, a table, and people. Which of these things has a temperature (a) lower than, (b) greater than, or (c) equal to the temperature of the air?
If you drop a hot rock into a pail of water, the temperature of the rock and the water will change until both are equal. The rock will cool and the water will warm. Does this hold true it the hot rock is dropped into the Atlantic Ocean? Explain.
Consider two glasses, one filled with water and the other half-full, with the water in the two glasses being at the same temperature. In which glass are the water molecules moving faster? In which is there greater internal energy? In which will more heat be required to increase the temperature by
Would you expect the temperature of water at the bottom of Niagara Falls to be slightly higher than the temperature at the top of the falls? Why?
Why does the pressure of gas enclosed in a rigid container increase as the temperature increases?
Adding the same amount of heat to two different objects does not necessarily produce the same increase in temperature. Why not?
Heat added to a substance goes partly into the translational kinetic energy of its molecules, which directly elevates temperature. For some substances, large proportions of heat also go into vibrations and rotations of the molecules. Would you expect materials in which a lot of energy goes into non
Why does a piece of watermelon stay cool for a longer time than sandwiches do when both arc removed from a picnic cooler on a hot day?
In times past, on a cold winter night, it was common to bring a hot object to bed with you. Which would keep you warmer through the cold night-a 10-kg iron brick or a 10-kg jug of hot water at the same temperature? Explain.
Bermuda is about as far north of the equator as North Carolina, but, unlike North Carolina, it has a subtropical climate year-round. Why is this so?
Why does the presence of large bodies of water tend to moderate the climate of nearby land-to make it warmer in cold weather and cooler in hot weather?
If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow only cherry trees and Washington, D.C., both cherry trees and palm trees?
Desert sand is very hot in the day and very cool at night. What does this indicate about its specific heat capacity?
Any architect will tell you that chimneys are never used as a weight-bearing part of a wall. Why?
Why wouldn't you expect all the molecules in a gas to have the same speed?
Would you or the gas company gain by having gas warmed before it passed through your gas meter?
A metal ball is just able to pass through a metal ring. When Anette increases the temperature of the ball, however, it will not pass through the ring. What would happen if she instead increased the temperature of the ring, rather than the ball? Will the size of the hole increase, stay the same, or
After a machinist very quickly slips a hot, snugly fitting iron ring over a very cold brass cylinder, there is no way that the two can be separated intact. Can you explain why this is so?
Suppose that you cut a small gap in a metal ring. If you were to heat the ring, would the gap become wider or narrower?
When a mercury thermometer is warmed, the mercury level momentarily goes down before it rises. Can you give an explanation for this?
One of the reasons the first light bulbs were expensive was due to the platinum electrical lead wires into the bulb, necessary because they expanded at about the same rate as glass when heated. Why is it important that the metal leads and the glass have the same coefficient of expansion?

Showing 4100 - 4200 of 7586

First
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
Last

Conceptual Physics 11th edition Paul G. Hewitt - Solutions

Step by Step Answers