Separate the list P, F, V, v, ?, T, a, m, L, t, and V into

Fundamentals of Thermodynamcs | 8th Edition | ISBN: 9781118131992 | Authors: Claus Borgnakke, Richard E. Sonntag

Chapter 1: Problem 4 Fundamentals of Thermodynamcs 8

Problem 4CGP A tray of liquid water is placed in a freezer where it cools from 20°C to ?5°C. Show the energy flow(s) and storage and explain what changes.

Chapter 1: Problem 3 Fundamentals of Thermodynamcs 8

Problem 3CGP Separate the list P, F, V, v, ?, T, a, m, L, t, and V into intensive properties, extensive properties, and nonproperties.

Chapter 1: Problem 129 Fundamentals of Thermodynamcs 8

Problem 129COP Plot the atmospheric pressure as a function of elevation (0–20 000 m) at a location where the ground pressure is 100 kPa at 500 m elevation. Use the variation shown in Problem 1.64. Problem 1.64 The standard pressure in the atmosphere with elevation (H) above sea level can be correlated as P = P0 (1 ? H/L) 5.26 with L = 44 300 m. With the local sea level pressure P0 at 101 kPa, what is the pressure at 10 000 m elevation?

Chapter 1: Problem 5 Fundamentals of Thermodynamcs 8

Problem 5CGP The overall density of fibers, rock wool insulation, foams, and cotton is fairly low. Why?

Chapter 1: Problem 6 Fundamentals of Thermodynamcs 8

Problem 6CGP Is density a unique measure of mass distribution in a volume? Does it vary? If so, on what kind of scale (distance)?

Chapter 1: Problem 1 Fundamentals of Thermodynamcs 8

Problem 1CGP Make a control volume around the whole power plant in Fig. 1.1 and list the flows of mass and energy in or out and any storage of energy. Make sure you know what is inside and what is outside your chosen control volume. FIGURE 1.1 A power station in Esbjerg, Denmark.

Chapter 1: Problem 7 Fundamentals of Thermodynamcs 8

Problem 7CGP Water in nature exists in three different phases: solid, liquid, and vapor (gas). Indicate the relative magnitude of density and the specific volume for the three phases.

Chapter 1: Problem 8 Fundamentals of Thermodynamcs 8

Problem 8CGP What is the approximate mass of 1 L of gasoline? Of helium in a balloon at T0, P0?

Chapter 1: Problem 9 Fundamentals of Thermodynamcs 8

Problem 9CGP Can you carry 1 m3 of liquid water?

Chapter 1: Problem 14 Fundamentals of Thermodynamcs 8

Problem 14CGP A manometer with water shows a ?P of P0/20; what is the column height difference?

Chapter 1: Problem 15 Fundamentals of Thermodynamcs 8

Problem 15CGP Does the pressure have to be uniform for equilibrium to exist?

Chapter 1: Problem 11 Fundamentals of Thermodynamcs 8

Problem 11CGP A swimming pool has an evenly distributed pressure at the bottom. Consider a stiff steel plate lying on the ground. Is the pressure below it just as evenly distributed?

Chapter 1: Problem 10 Fundamentals of Thermodynamcs 8

Problem 10CGP A heavy refrigerator has four height-adjustable feet. What feature of the feet will ensure that they do not make dents in the floor?

Chapter 1: Problem 13 Fundamentals of Thermodynamcs 8

Problem 13CGP Two divers swim at a depth of 20 m. One of them swims directly under a supertanker; the other avoids the tanker. Who feels a greater pressure?

Chapter 1: Problem 12 Fundamentals of Thermodynamcs 8

Problem 12CGP What physically determines the variation of the atmospheric pressure with elevation?

Chapter 1: Problem 16 Fundamentals of Thermodynamcs 8

Problem 16CGP A water skier does not sink too far down in the water if the speed is high enough. What makes that situation different from our static pressure calculations?

Chapter 1: Problem 17 Fundamentals of Thermodynamcs 8

Problem 17CGP What is the lowest temperature in degrees Celsius? In degrees Kelvin?

Chapter 1: Problem 18 Fundamentals of Thermodynamcs 8

Problem 18CGP Convert the formula for water density in In-Text Concept Problem d to be for T in degrees Kelvin.

Chapter 1: Problem 20 Fundamentals of Thermodynamcs 8

Problem 20CGP What is the main difference between the macroscopic kinetic energy in a motion like the blowing of wind versus the microscopic kinetic energy of individual molecules? Which one can you sense with your hand?

Chapter 1: Problem 19 Fundamentals of Thermodynamcs 8

Problem 19CGP A thermometer that indicates the temperature with a liquid column has a bulb with a larger volume of liquid. Why?

Chapter 1: Problem 22 Fundamentals of Thermodynamcs 8

Problem 22HP An apple “weighs” 60 g and has a volume of 75 cm3 in a refrigerator at 8°C. What is the apple’s density? List three intensive and two extensive properties of the apple.

Chapter 1: Problem 23 Fundamentals of Thermodynamcs 8

Problem 23HP One kilopond (1 kp) is the weight of 1 kg in the standard gravitational field. What is the weight of 1 kg in newtons (N)?

Chapter 1: Problem 21 Fundamentals of Thermodynamcs 8

Problem 21CGP How can you illustrate the binding energy between the three atoms in water as they sit in a triatomic water molecule. Hint: imagine what must happen to create three separate atoms.

Chapter 1: Problem 24 Fundamentals of Thermodynamcs 8

Problem 24HP A stainless steel storage tank contains 5 kg of oxygen gas and 7 kg of nitrogen gas. How many kmoles are in the tank?

Chapter 1: Problem 25 Fundamentals of Thermodynamcs 8

Problem 25HP A steel cylinder of mass 4 kg contains 4 L of water at 25°C at 100 kPa. Find the total mass and volume of the system. List two extensive and three intensive properties of the water.

Chapter 1: Problem 26 Fundamentals of Thermodynamcs 8

Problem 26HP The standard acceleration (at sea level and 45° latitude) due to gravity is 9.806 65 m/s2. What is the force needed to hold a mass of 2 kg at rest in this gravitational field? How much mass can force of 1 N support?

Chapter 1: Problem 27 Fundamentals of Thermodynamcs 8

Problem 27HP An aluminum piston of 2.5 kg is in the standard gravitational field, and a force of 25 N is applied vertically up. Find the acceleration of the piston.

Chapter 1: Problem 30 Fundamentals of Thermodynamcs 8

Problem 30HP A van moves at 60 km/h and completely stops with constant deceleration in 5 s. The mass of the van and driver is 2075 kg, find the necessary force.

Chapter 1: Problem 29 Fundamentals of Thermodynamcs 8

Problem 29HP A car rolls down a hill with a slope such that the gravitational “pull” in the direction of motion is one-tenth of the standard gravitational force (see Problem 1.26). If the car has a mass of 2500 kg, find the acceleration. Problem 1.26 The standard acceleration (at sea level and 45° latitude) due to gravity is 9.806 65 m/s2. What is the force needed to hold a mass of 2 kg at rest in this gravitational field? How much mass can a force of 1 N support?

Chapter 1: Problem 28 Fundamentals of Thermodynamcs 8

Problem 28HP When you move up from the surface of the earth, the gravitation is reduced as g = 9.807 ? 3.32 × 10?6 z, with z being the elevation in meters. By what percentage is the weight of an airplane reduced when it cruises at 11 000 m?

Chapter 1: Problem 31 Fundamentals of Thermodynamcs 8

Problem 31HP A 1500 kg car moving at 20 km/h is accelerated at a constant rate of 4 m/s2 up to a speed of 75 km/h. What are the force and total time required?

Chapter 1: Problem 33 Fundamentals of Thermodynamcs 8

Problem 33HP The elevator in a hotel has a mass of 750 kg, and it carries six people with a total mass of 450 kg. How much force should the cable pull up with to have an acceleration of 1 m/s2 in the upward direction?

Chapter 1: Problem 32 Fundamentals of Thermodynamcs 8

Problem 32HP On the moon, the gravitational acceleration is approximately one-sixth that on the surface of the earth. A 5-kg mass is “weighed” with a beam balance on the surface of the moon. What is the expected reading? If this mass is weighed with a spring scale that reads correctly for standard gravity on earth (see Problem 1.26), what is the reading? Problem 1.26 The standard acceleration (at sea level and 45° latitude) due to gravity is 9.806 65 m/s2. What is the force needed to hold a mass of 2 kg at rest in this gravitational field? How much mass can a force of 1 N support?

Chapter 1: Problem 34 Fundamentals of Thermodynamcs 8

Problem 34HP One of the people in the previous problem weighs 80 kg standing still. How much weight does this person feel when the elevator starts moving?

Chapter 1: Problem 35 Fundamentals of Thermodynamcs 8

Problem 35HP A bottle of 12 kg steel has 1.75 kmoles of liquid propane. It accelerates horizontally at a rate of 3 m/s2. What is the needed force?

Chapter 1: Problem 36 Fundamentals of Thermodynamcs 8

Problem 36HP A steel beam of 700 kg is raised by a crane with an acceleration of 2 m/s2 relative to the ground at a location where the local gravitational acceleration is 9.5 m/s2. Find the required force.

Chapter 1: Problem 38 Fundamentals of Thermodynamcs 8

Problem 38HP A power plant that separates carbon dioxide from the exhaust gases compresses it to a density of 110 kg/m3 and stores it in an unminable coal seam with a porous volume of 100 000 m3. Find the mass that can be stored.

Chapter 1: Problem 37 Fundamentals of Thermodynamcs 8

A 1-m3 container is filled with 400 kg of granite stone, 200 kg of dry sand, and 0.2 m3 of liquid 25°C water. Using properties from Tables A.3 and A.4, find the average specific volume and density of the masses when you exclude air mass and volume.

Chapter 1: Problem 39 Fundamentals of Thermodynamcs 8

Problem 39HP A 15-kg steel gas tank holds 300 L of liquid gasoline with a density of 800 kg/m3. If the system is decelerated with 2g, what is the needed force?

Chapter 1: Problem 40 Fundamentals of Thermodynamcs 8

Problem 40HP A 5-m3 container is filled with 900 kg of granite (density of 2400 kg/m3). The rest of the volume is air, with density equal to 1.15 kg/m3. Find the mass of air and the overall (average) specific volume.

Chapter 1: Problem 42 Fundamentals of Thermodynamcs 8

Problem 42HP One kilogram of diatomic oxygen (O2, molecular mass of 32) is contained in a 500-L tank. Find the specific volume on both a mass and a mole basis (v and ?).

Chapter 1: Problem 43 Fundamentals of Thermodynamcs 8

Problem 43HP A 5000-kg elephant has a cross-sectional area of 0.02 m2 on each foot. Assuming an even distribution, what is the pressure under its feet?

Chapter 1: Problem 41 Fundamentals of Thermodynamcs 8

Problem 41HP A tank has two rooms separated by a membrane. Room A has 1 kg of air and a volume of 0.5 m3; room B has 0.75 m3 of air with density 0.8 kg/m3. The membrane is broken, and the air comes to a uniform state. Find the final density of the air.

Chapter 1: Problem 44 Fundamentals of Thermodynamcs 8

Problem 44HP A valve in the cylinder shown in Fig. P1.44 has a cross-sectional area of 11 cm2 with a pressure of 735 kPa inside the cylinder and 99 kPa outside. How large a force is needed to open the valve? FIGURE P1.44

Chapter 1: Problem 45 Fundamentals of Thermodynamcs 8

Problem 45HP The hydraulic lift in an auto repair shop has a cylinder diameter of 0.2 m. To what pressure should the hydraulic fluid be pumped to lift 40 kg of piston/ arms and 700 kg of a car?

Chapter 1: Problem 46 Fundamentals of Thermodynamcs 8

Problem 46HP A hydraulic lift has a maximum fluid pressure of 500 kPa. What should the piston/cylinder diameter be in order to lift a mass of 850 kg?

Chapter 1: Problem 47 Fundamentals of Thermodynamcs 8

Problem 47HP A laboratory room has a vacuum of 0.1 kPa. What net force does that put on the door of size 2 m by 1 m?

Chapter 1: Problem 48 Fundamentals of Thermodynamcs 8

Problem 48HP A vertical hydraulic cylinder has a 125-mmdiameter piston with hydraulic fluid inside the cylinder and an ambient pressure of 1 bar. Assuming standard gravity, find the piston mass that will create an inside pressure of 1500 kPa.

Chapter 1: Problem 51 Fundamentals of Thermodynamcs 8

Problem 51HP A large exhaust fan in a laboratory room keeps the pressure inside at 10 cm of water vacuum relative to the hallway. What is the net force on the door measuring 1.9 m by 1.1 m?

Chapter 1: Problem 49 Fundamentals of Thermodynamcs 8

Problem 49HP A 75-kg human total footprint is 0.05 m2 when the human is wearing boots. Suppose you want to walk on snow that can at most support an extra 3 kPa; what should the total snowshoe area be?

Chapter 1: Problem 50 Fundamentals of Thermodynamcs 8

Problem 50HP A piston/cylinder with a cross-sectional area of 0.01 m2 has a piston mass of 100 kg resting on the stops, as shown in Fig. P1.50. With an outside atmospheric pressure of 100 kPa, what should the water pressure be to lift the piston? FIGURE P1.50

Chapter 1: Problem 52 Fundamentals of Thermodynamcs 8

Problem 52HP A tornado rips off a 100-m2 roof with a mass of 1000 kg. What is the minimum vacuum pressure needed to do that ifwe neglect the anchoring forces?

Chapter 1: Problem 53 Fundamentals of Thermodynamcs 8

Problem 53HP A5-kg cannonball acts as a piston in a cylinder with a diameter of 0.15 m. As the gunpowder is burned, a pressure of 7 MPa is created in the gas behind the ball. What is the acceleration of the ball if the cylinder (cannon) is pointing horizontally?

Chapter 1: Problem 54 Fundamentals of Thermodynamcs 8

Problem 54HP Repeat the previous problem for a cylinder (cannon) pointing 40° up relative to the horizontal direction.

Chapter 1: Problem 55 Fundamentals of Thermodynamcs 8

Problem 55HP A 2.5-m-tall steel cylinder has a cross-sectional area of 1.5m2. At the bottom, with a height of 0.5 m, is liquid water, on top of which is a 1-m-high layer of gasoline. This is shown in Fig. P1.55. The gasoline surface is exposed to atmospheric air at 101 kPa. What is the highest pressure in the water? FIGURE P1.55

Chapter 1: Problem 58 Fundamentals of Thermodynamcs 8

Problem 58HP What is the pressure at the bottom of a 5-m-tall column of fluid with atmospheric pressure of 101 kPa on the top surface if the fluid is a. water at 20°C? b. glycerine at 25°C? c. gasoline at 25°C?

Chapter 1: Problem 56 Fundamentals of Thermodynamcs 8

Problem 56HP An underwater buoy is anchored at the seabed with a cable, and it contains a total mass of 250 kg. What should the volume be so that the cable holds it down with a force of 1000 N?

Chapter 1: Problem 57 Fundamentals of Thermodynamcs 8

Problem 57HP At the beach, atmospheric pressure is 1025 mbar. You dive 15 m down in the ocean, and you later climb a hill up to 250 m in elevation. Assume that the density of water is about 1000 kg/m3 and the density of air is 1.18 kg/m3. What pressure do you feel at each place?

Chapter 1: Problem 59 Fundamentals of Thermodynamcs 8

Problem 59HP A steel tank of cross-sectional area 3 m2 and height 16 m weighs 10 000 kg and is open at the top, as shown in Fig. P1.59. We want to float it in the ocean so that it is positioned 10 m straight down by pouring concrete into its bottom. How much concrete should we use? FIGURE P1.59

Chapter 1: Problem 60 Fundamentals of Thermodynamcs 8

Problem 60HP A piston, mp = 5 kg, is fitted in a cylinder, A = 15 cm2, that contains a gas. The setup is in a centrifuge that creates an acceleration of 25 m/s2 in the direction of piston motion toward the gas. Assuming standard atmospheric pressure outside the cylinder, find the gas pressure.

Chapter 1: Problem 61 Fundamentals of Thermodynamcs 8

Problem 61HP Liquid water with density ?is filled on top of a thin piston in a cylinder with cross-sectional area A and total height H, as shown in Fig. P1.61. Air is let in under the piston so that it pushes up, causing the water to spill over the edge. Derive the formula for the air pressure as a function of piston elevation from the bottom, h. FIGURE P1.61

Chapter 1: Problem 62 Fundamentals of Thermodynamcs 8

Problem 62HP A probe is lowered 16 m into a lake. Find the absolute pressure there.

Chapter 1: Problem 63 Fundamentals of Thermodynamcs 8

Problem 63HP The density of atmospheric air is about 1.15 kg/m3, which we assume is constant. How large an absolute pressure will a pilot encounter when flying 2000 m above ground level, where the pressure is 101 kPa?

Chapter 1: Problem 64 Fundamentals of Thermodynamcs 8

Problem 64HP The standard pressure in the atmosphere with elevation (H) above sea level can be correlated as P = P0 (1 ? H/L) 5.26 with L = 44 300 m. With the local sea level pressure P0 at 101 kPa, what is the pressure at 10 000 m elevation?

Chapter 1: Problem 65 Fundamentals of Thermodynamcs 8

Problem 65HP A barometer to measure absolute pressure shows a mercury column height of 725 mm. The temperature is such that the density of the mercury is 13 550 kg/m3. Find the ambient pressure.

Chapter 1: Problem 66 Fundamentals of Thermodynamcs 8

Problem 66HP A differential pressure gauge mounted on a vessel shows 1.25 MPa, and a local barometer gives atmospheric pressure as 0.96 bar. Find the absolute pressure inside the vessel.

Chapter 1: Problem 67 Fundamentals of Thermodynamcs 8

Problem 67HP A manometer shows a pressure difference of 1 m of liquid mercury. Find ?P in kPa.

Chapter 1: Problem 69 Fundamentals of Thermodynamcs 8

Problem 69HP What pressure difference does a 10-m column of atmospheric air show?

Chapter 1: Problem 70 Fundamentals of Thermodynamcs 8

Problem 70HP A barometer measures 760 mm Hg at street level and 735 mm Hg on top of a building. How tall is the building if we assume air density of 1.15 kg/m3?

Chapter 1: Problem 68 Fundamentals of Thermodynamcs 8

Problem 68HP Blue manometer fluid of density 925 kg/m3 shows a column height difference of 3-cm vacuum with one end attached to a pipe and the other open to P0 = 101 kPa. What is the absolute pressure in the pipe?

Chapter 1: Problem 71 Fundamentals of Thermodynamcs 8

Problem 71HP The pressure gauge on an air tank shows 75 kPa when the diver is 10 m down in the ocean. At what depth will the gauge pressure be zero? What does that mean?

Chapter 1: Problem 72 Fundamentals of Thermodynamcs 8

Problem 72HP An exploration submarine should be able to descend 1200 m down in the ocean. If the ocean density is 1020 kg/m3, what is the maximum pressure on the submarine hull?

Chapter 1: Problem 73 Fundamentals of Thermodynamcs 8

Problem 73HP A submarine maintains an internal pressure of 101 kPa and dives 240 m down in the ocean, which has an average density of 1030 kg/m3. What is the pressure difference between the inside and the outside of the submarine hull?

Chapter 1: Problem 74 Fundamentals of Thermodynamcs 8

Problem 74HP Assume that we use a pressure gauge to measure the air pressure at street level and at the roof of a tall building. If the pressure difference can be determined with an accuracy of 1 mbar (0.001 bar), what uncertainty in the height estimate does that correspond to?

Chapter 1: Problem 75 Fundamentals of Thermodynamcs 8

Problem 75HP The absolute pressure in a tank is 115 kPa and the local ambient absolute pressure is 97 kPa. If a U-tube with mercury (density = 13 550 kg/m3) is attached to the tank to measure the gauge pressure, what column height difference will it show?

Chapter 1: Problem 76 Fundamentals of Thermodynamcs 8

Problem 76HP An absolute pressure gauge attached to a steel cylinder shows 135 kPa. We want to attach a manometer using liquid water on a day that Patm = 101 kPa. How high a fluid level difference must we plan for?

Chapter 1: Problem 77 Fundamentals of Thermodynamcs 8

Problem 77HP A U-tube manometer filled with water (density = 1000 kg/m3) shows a height difference of 25 cm. What is the gauge pressure? If the right branch is tilted to make an angle of 30° with the horizontal, as shown in Fig. P1.77, what should the length of the column in the tilted tube be relative to the U-tube? FIGURE P1.77

Chapter 1: Problem 79 Fundamentals of Thermodynamcs 8

Problem 79HP The difference in height between the columns of a manometer is 200 mm, with a fluid of density 900 kg/m3. What is the pressure difference? What is the height difference if the same pressure difference is measured using mercury (density = 13 600 kg/m3) as manometer fluid?

Chapter 1: Problem 78 Fundamentals of Thermodynamcs 8

Problem 78HP A pipe flowing light oil has a manometer attached, as shown in Fig. P1.78. What is the absolute pressure in the pipe flow? FIGURE P1.78

Chapter 1: Problem 83 Fundamentals of Thermodynamcs 8

Problem 83HP A piece of experimental apparatus, Fig. P1.83, is located where g = 9.5 m/s2 and the temperature is 5°C. Air flow inside the apparatus is determined by measuring the pressure drop across an orifice with a mercury manometer (see Problem 1.91 for density) showing a height difference of 200 mm. What is the pressure drop in kPa? FIGURE P1.83 Problem 1.91 The density of mercury changes approximately linearly with temperature as ?Hg = 13 595 – 2.5 T kg/m3 (T in Celsius), so the same pressure difference will result in a manometer reading that is influenced by temperature. If a pressure difference of 100 kPa is measured in the summer at 35°C and in the winter at ?15°C, what is the difference in column height between the two measurements?

Chapter 1: Problem 84 Fundamentals of Thermodynamcs 8

Problem 84HP An escalator brings four people, whose total mass is 300 kg, 25 m up in a building. Explain what happens with respect to energy transfer and stored energy.

Chapter 1: Problem 85 Fundamentals of Thermodynamcs 8

Problem 85HP A car moves at 75 km/h; its mass, including people, is 3200 kg. How much kinetic energy does the car have?

Chapter 1: Problem 80 Fundamentals of Thermodynamcs 8

Problem 80HP Two cylinders are filled with liquid water, ? =1000 kg/m3, and connected by a line with a closed valve, as shown in Fig. P1.80. A has 100 kg and B has 500 kg of water, their cross-sectional areas are AA =0.1m2 and AB =0.25m2, and the height h is 1 m. Find the pressure on either side of the valve. The valve is opened, and water flows to an equilibrium. Find the final pressure at the valve location. FIGURE P1.80

Chapter 1: Problem 81 Fundamentals of Thermodynamcs 8

Problem 81HP Two piston/cylinder arrangements, A and B, have their gas chambers connected by a pipe, as shown in Fig. P1.81. The cross-sectional areas are AA = 75 cm2 and AB = 25 cm2, with the piston mass in A being mA = 25 kg. Assume an outside pressure of 100 kPa and standard gravitation. Find the mass mB so that none of the pistons have to rest on the bottom. FIGURE P1.81

Chapter 1: Problem 82 Fundamentals of Thermodynamcs 8

Problem 82HP Two hydraulic piston/cylinders are of the same size and setup as in Problem 1.81, but with negligible piston masses. A single point force of 250 N presses down on piston A. Find the needed extra force on piston B so that none of the pistons have to move. Problem 1.81 Two piston/cylinder arrangements, A and B, have their gas chambers connected by a pipe, as shown in Fig. P1.81. The cross-sectional areas are AA = 75 cm2 and AB = 25 cm2, with the piston mass in A being mA = 25 kg. Assume an outside pressure of 100 kPa and standard gravitation. Find the mass mB so that none of the pistons have to rest on the bottom. FIGURE P1.81

Chapter 1: Problem 86 Fundamentals of Thermodynamcs 8

Problem 86HP A 52-kg package is lifted up to the top shelf in a storage bin that is 4 m above the ground floor. How much increase in potential energy does the package get?

Chapter 1: Problem 87 Fundamentals of Thermodynamcs 8

Problem 87HP A car of mass 1775 kg travels with a velocity of 100 km/h. Find the kinetic energy. Howhigh should the car be lifted in the standard gravitational field to have a potential energy that equals the kinetic energy?

Chapter 1: Problem 88 Fundamentals of Thermodynamcs 8

Problem 88HP An oxygen molecule with mass m = M mo = 32 × 1.66 × 10?27 kg moves with a velocity of 240 m/s. What is the kinetic energy of the molecule? What temperature does that corresponds to if it has to equal (3/2) kT, where k is Boltzmans constant and T is absolute temperature in Kelvin?

Chapter 1: Problem 89 Fundamentals of Thermodynamcs 8

Problem 89HP What is a temperature of ?5°C in degrees Kelvin?

Chapter 1: Problem 90 Fundamentals of Thermodynamcs 8

Problem 90HP The human comfort zone is between 18 and 24°C. What is the range in Kelvin? What is the maximum relative change from the low to the high temperature?

Chapter 1: Problem 91 Fundamentals of Thermodynamcs 8

Problem 91HP The density of mercury changes approximately linearly with temperature as ?Hg = 13 595 – 2.5 T kg/m3 (T in Celsius), so the same pressure difference will result in a manometer reading that is influenced by temperature. If a pressure difference of 100 kPa is measured in the summer at 35°C and in the winter at ?15°C, what is the difference in column height between the two measurements?

Chapter 1: Problem 93 Fundamentals of Thermodynamcs 8

Problem 93HP The density of liquid water is ? = 1008 ? T/2 [kg/m3] with T in °C. If the temperature increases 10°C, how much deeper does a 1-m layer of water become?

Chapter 1: Problem 92 Fundamentals of Thermodynamcs 8

Problem 92HP A mercury thermometer measures temperature by measuring the volume expansion of a fixed mass of liquid mercury due to a change in density (see Problem 1.91). Find the relative change (%) in volume for a change in temperature from 10°C to 20°C. Problem 1.91 The density of mercury changes approximately linearly with temperature as ?Hg = 13 595 – 2.5 T kg/m3 (T in Celsius), so the same pressure difference will result in a manometer reading that is influenced by temperature. If a pressure difference of 100 kPa is measured in the summer at 35°C and in the winter at ?15°C, what is the difference in column height between the two measurements?

Chapter 1: Problem 94 Fundamentals of Thermodynamcs 8

Problem 94HP Using the freezing and boiling point temperatures for water on both the Celsius and Fahrenheit scales, develop a conversion formula between the scales. Find the conversion formula between the Kelvin and Rankine temperature scales.

Chapter 1: Problem 97 Fundamentals of Thermodynamcs 8

Problem 97HP A dam retains a lake 6 m deep, as shown in Fig. P1.97.To construct a gate in the dam, we need to know the net horizontal force on a 5-m-wide, 6-m-tall port section that then replaces a 5-m section of the dam. Find the net horizontal force from the water on one side and air on the other side of the port. FIGURE P1.97

Chapter 1: Problem 95 Fundamentals of Thermodynamcs 8

Problem 95HP The atmosphere becomes colder at higher elevations. As an average, the standard atmospheric absolute temperature can be expressed as Tatm = 288 ? 6.5×10?3 z, where z is the elevation in meters. How cold is it outside an airplane cruising at 12 000 m, expressed in degrees Kelvin and Celsius?

Chapter 1: Problem 96 Fundamentals of Thermodynamcs 8

Problem 96HP Repeat Problem 1.83 if the flow inside the apparatus is liquid water (? = 1000 kg/m3) instead of air. Find the pressure difference between the two holes flush with the bottom of the channel. You cannot neglect the two unequal water columns. Problem 1.83 A piece of experimental apparatus, Fig. P1.83, is located where g = 9.5 m/s2 and the temperature is 5°C. Air flow inside the apparatus is determined by measuring the pressure drop across an orifice with a mercury manometer (see Problem 1.91 for density) showing a height difference of 200 mm. What is the pressure drop in kPa? FIGURE P1.83 Problem 1.91 The density of mercury changes approximately linearly with temperature as ?Hg = 13 595 – 2.5 T kg/m3 (T in Celsius), so the same pressure difference will result in a manometer reading that is influenced by temperature. If a pressure difference of 100 kPa is measured in the summer at 35°C and in the winter at ?15°C, what is the difference in column height between the two measurements?

Chapter 1: Problem 99 Fundamentals of Thermodynamcs 8

Problem 99HP The main waterline into a tall building has a pressure of 600 kPa at 5-m elevation belowground level. The building is shown in Fig. P1.99. How much extra pressure does a pump need to add to ensure a waterline pressure of 200 kPa at the top floor 150 m aboveground? FIGURE P1.99

Chapter 1: Problem 98 Fundamentals of Thermodynamcs 8

Problem 98HP In the city water tower, water is pumped up to a level 25 m above ground in a pressurized tank with air at 125 kPa over the water surface. This is illustrated in Fig. P1.98. Assuming water density of 1000 kg/m3 and standard gravity, find the pressure required to pump more water in at ground level. FIGURE P1.98

Chapter 1: Problem 101 Fundamentals of Thermodynamcs 8

Problem 101HP A 5-kg piston in a cylinder with a diameter of 100 mm is loaded with a linear spring and the outside atmospheric pressure is 100 kPa, as shown in Fig. P1.101. The spring exerts no force on the piston when it is at the bottom of the cylinder, and for the state shown, the pressure is 400 kPa with volume 0.4 L. The valve is opened to let some air in, causing the piston to rise 2 cm. Find the new pressure. FIGURE P1.101

Chapter 1: Problem 100 Fundamentals of Thermodynamcs 8

Problem 100HP Two cylinders are connected by a piston, as shown in Fig. P1.100. Cylinder A is used as a hydraulic lift and pumped up to 500 kPa. The piston mass is 25 kg, and there is standard gravity. What is the gas pressure in cylinder B? FIGURE P1.100

Chapter 1: Problem 102 Fundamentals of Thermodynamcs 8

Problem 102EUP A mass of 2 lbm has an acceleration of 5 ft/s2. What is the needed force in lbf ?

Chapter 1: Problem 103 Fundamentals of Thermodynamcs 8

Problem 103EUP How much mass is in 1 gal of gasoline? In helium in a balloon at atmospheric P and T?

Chapter 1: Problem 104 Fundamentals of Thermodynamcs 8

Problem 104EUP Can you easily carry a 1-gal bar of solid gold?

Chapter 1: Problem 105 Fundamentals of Thermodynamcs 8

Problem 105EUP What is the temperature of ?5 F in degrees Rankine?

Chapter 1: Problem 106 Fundamentals of Thermodynamcs 8

Problem 106EUP What is the lowest possible temperature in degrees Fahrenheit? In degrees Rankine?

Chapter 1: Problem 108 Fundamentals of Thermodynamcs 8

Problem 108EUP Chemical reaction rates generally double for a 10-K increase in temperature. How large an increase is that in Fahrenheit?

Chapter 1: Problem 107 Fundamentals of Thermodynamcs 8

Problem 107EUP What is the relative magnitude of degree Rankine to degree Kelvin?

Chapter 1: Problem 109 Fundamentals of Thermodynamcs 8

Problem 109EUP An apple weighs 0.2 lbm and has a volume of 6 in.3 in a refrigerator at 38 F. What is the apple’s density? List three intensive and two extensive properties of the apple.

Chapter 1: Problem 110 Fundamentals of Thermodynamcs 8

Problem 110EUP A steel piston of mass 10 lbm is in the standard gravitational field, where a force of 10 lbf is applied vertically up. Find the acceleration of the piston.

Chapter 1: Problem 111 Fundamentals of Thermodynamcs 8

Problem 111EUP A 2500-lbm car moving at 25 mi/h is accelerated at a constant rate of 15 ft/s2 up to a speed of 50 mi/h. What are the force and total time required?

Chapter 1: Problem 112 Fundamentals of Thermodynamcs 8

Problem 112EUP An escalator brings four people with a total mass of 600 lbm and a 1000-lbm cage up with an acceleration of 3 ft/s2. What is the needed force in the cable?

Chapter 1: Problem 114 Fundamentals of Thermodynamcs 8

Problem 114EUP A30-lbm steel gas tank holds 10 ft3 of liquid gasoline having a density of 50 lbm/ft3. What force is needed to accelerate this combined system at a rate of 15 ft/s2?

Chapter 1: Problem 113 Fundamentals of Thermodynamcs 8

Problem 113EUP A 1-lbm of diatomic oxygen (O2 molecular mass 32) is contained in a 100-gal tank. Find the specific volume on both a mass and a mole basis (v and ?).

Chapter 1: Problem 115 Fundamentals of Thermodynamcs 8

Problem 115EUP A power plant that separates carbon dioxide from the exhaust gases compresses it to a density of 8 lbm/ft3 and stores it in an unminable coal seam with a porous volume of 3 500 000 ft3. Find the mass that can be stored.

Chapter 1: Problem 116 Fundamentals of Thermodynamcs 8

Problem 116EUP A laboratory room keeps a vacuum of 4 in. of water due to the exhaust fan. What is the net force on a door of size 6 ft by 3 ft?

Chapter 1: Problem 118 Fundamentals of Thermodynamcs 8

Problem 118EUP A tornado rips off a 1000-ft2 roof with a mass of 2000 lbm. What is the minimum vacuum pressure needed to do that if we neglect the anchoring forces?

Chapter 1: Problem 117 Fundamentals of Thermodynamcs 8

Problem 117EUP A 150-lbm human total footprint is 0.5 ft2 when the person is wearing boots. If snow can support an extra 1 psi, what should the total snowshoe area be?

Chapter 1: Problem 120 Fundamentals of Thermodynamcs 8

Problem 120EUP A 7-ft tall steel cylinder has a cross-sectional area of 15 ft2. At the bottom, with a height of 2 ft, is liquid water, on top of which is a 4-ft-high layer of gasoline. The gasoline surface is exposed to atmospheric air at 14.7 psia. What is the highest pressure in the water?

Chapter 1: Problem 121 Fundamentals of Thermodynamcs 8

Problem 121EUP A U-tube manometer filled with water, density 62.3 lbm/ft3, shows a height difference of 10 in. What is the gauge pressure? If the right branch is tilted to make an angle of 30° with the horizontal, as shown in Fig. P1.77, what should the length of the column in the tilted tube be relative to the U-tube? FIGURE P1.77

Chapter 1: Problem 122 Fundamentals of Thermodynamcs 8

Problem 122EUP A piston/cylinder with a cross-sectional area of 0.1 ft2 has a piston mass of 200 lbm resting on the stops, as shown in Fig. P1.50. With an outside atmospheric pressure of 1 atm, what should the water pressure be to lift the piston? FIGURE P1.50

Chapter 1: Problem 124 Fundamentals of Thermodynamcs 8

Problem 124EUP A piston, mp = 10 lbm, is fitted in a cylinder, A = 2.5 in.2, that contains a gas. The setup is in a centrifuge that creates an acceleration of 75 ft/s2. Assuming standard atmospheric pressure outside the cylinder, find the gas pressure.

Chapter 1: Problem 123 Fundamentals of Thermodynamcs 8

Problem 123EUP The main waterline into a tall building has a pressure of 90 psia at 16 ft elevation below ground level. How much extra pressure does a pump need to add to ensure a waterline pressure of 30 psia at the top floor 450 ft above ground?

Chapter 1: Problem 125 Fundamentals of Thermodynamcs 8

Problem 125EUP The human comfort zone is between 18 and 24°C. What is the range in Fahrenheit?

Chapter 1: Problem 127 Fundamentals of Thermodynamcs 8

Problem 127EUP The density of mercury changes approximately linearly with temperature as ?Hg =851.5?0.086 T lbm/ ft3 (T in degrees Fahrenheit), so the same pressure difference will result in a manometer reading that is influenced by temperature. If a pressure difference of 14.7 lbf/in.2 is measured in the summer at 95 F and in the winter at 5 F, what is the difference in column height between the two measurements?

Chapter 1: Problem 126 Fundamentals of Thermodynamcs 8

Problem 126EUP The atmosphere becomes colder at higher elevations. As an average, the standard atmospheric absolute temperature can be expressed as Tatm = 518 ? 3.84 × 10?3 z, where z is the elevation in feet. How cold is it outside an airplane cruising at 32 000 ft expressed in degrees Rankine and Fahrenheit?

Chapter : Problem 119 Fundamentals of Thermodynamcs 8

Problem 119EUP A manometer shows a pressure difference of 3.5 in. of liquid mercury. Find ?P in psi.

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Textbook Solutions for Fundamentals of Thermodynamcs

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Separate the list P, F, V, v, ?, T, a, m, L, t, and V into

Chapter 1 textbook questions

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Textbook Solutions for Fundamentals of Thermodynamcs

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Solution

Separate the list P, F, V, v, ?, T, a, m, L, t, and V into

Chapter 1 textbook questions

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