VIP 1-7
問題一覧
1
Det the specific weight of air at 760mmhg absoulte and 22C
1.197 kg/cm3
2
Find the Enthalphy of helium if its internal energy is 200 kj/kg
333.42 kj/kg
3
Compute the mass of a 2 m propane at 280 kPa and 40°C
9.47 kg
4
Find the pressure at the 100 fathom depth of water in kpag.
1,793.96
5
Find the depth in furlong of the ocean (SG = 1.03) if the pressure at the sea bed is 2,032.56 kpag.
1
6
A 1mx 1.5m cylindrical tank is full of oil with SG = 0.92. Find the force acting at the bottom of the tank in dynes.
106.33 x 10⁶
7
Find the mass of ten quartz of water
9.46 kg
8
Find the mass of carbon dioxide having a pressure of 20psia at 200°F with 10 ft³ volume
1.24 lb
9
What is the approximate value of temperature of water having enthalpy of 208 Btu/Ib?
115.55
10
Camot cycle A, B, and C are connected in series sa that the heat rejected from A will be the heat added to B and heat rejected frorn B will be added to C, each cycle operatesbetween 30°C to 400°C. If heat added to A is 1000 kw, find the work outpit of °C
111.44
11
Two kilogram of air in a figid tank changes its temperature from 32°C to 150°C. Find the work done during the process
0
12
Determine the atmospheric pressure at a location where barometric reading is 740 mm Hg and gravitational acceleration is g = 9.7 m/s?. Assume the temperature of mercury to be 10°C, at which the density is 13,670 kg/m³
97.41 kPa
13
An Ideal gas at 0.80 atmospheres and 87°C 0.450 liter. How many moles are In the sample? (R = 0.0821 liter-atm/mole-K)
0.0122
14
A certain gas at 101.325 kPa and 10°C whose volume is 2.83 m³ are compressed into a storage vessel at 0.31 m³ capacity. Before admission, the storage vessel contained the gas at a pressure and temperature of 137.8 kPa and 26°C, after admission the pressure has increased to 1171.6 kPa. What should be the final temperature of the gas in the
vessel In Kelvin?
314.2 K
15
A perfect gas has a value of R = 58.8 ft-Ib/Ib-°R and k =1.26. If 20 Btu are added to 10 Ibs of the gas at constant volume when Initial temperature is 90°F, find the final
97°F
16
Ammonia weighing 22 kgs Is confirmed inside a cylinder equipped with a piston has an initial pressure of 413 kPa at 38°C. If 3200 KJ of heat is added to the ammonia until its final pressure and temperature are 413 kPa at 100°C, respectively: what is the amount of work done by the fluid in kJ
667
17
A tank contains 90 ft of air at a pressure of 350 psig. If the air is cooled until its pressure and temperature decreases to 200 psig and 70°F, respectively, what is the decrease in Internal energy?
-6232.09 BTU
18
A large mining company was provided with a 3 m³ of compressed air tank. Air pressure in the tank drops from 700 kPa to 150 kPa while the temperature remains constant
at 28°C. What percentage has the mass of air in the tank been reduced?
78.57
19
A 4 m³/hr pump delivers water to a pressure tank. At the start, the gage reads 138 kPa unil it reads 276 kPa and then the pump was shut off. The volume of the tank is 180 liters. At 276 kPa the water occupied 2/3 of the tank volume. Determine the volume of water that can be taken out until the gage reads 138 kPa.
34.59 liters
20
Atmospheric pressure boils at 212°F. At the vacuum pressure at 24 in Hg, the temperature is 142°F. Find the boiling temperature when the pressure is increased by 40 psia from atmospheric.
449.42 F
21
Find the work posses for a Helium gas at 20 deg C.
609 kg
22
What is the hydraulic gradient of a 1 mile, 17 inches inside diameter pipe when 3300 gal/min of water flow with f = 0.003
0.00714 miles
23
Convert 750°R to °K.
416.33
24
Air Is compressed adiabatically from 30°C to 100°C. If mass of air being compressed is 5 kg. And the change in entropy
0
25
A steam condenser receives 10 kg/s of steam with an enthalpy of 2770 kJ/kg. Steam condenses into a liquid and leaves with an enthalpy of 160 kJ/kg. Cooling water passes through the condenser with temperature increases from 13°C to 24°C. Calculate the water flow rate In kg/s.
567
26
If the initial volume of an ideal gas is compressed to one-half its original volume and to twice its temperature, the pressure:
Quadruples
27
If the gage pressure of a medium is 30 kPa (vacuum) and the atmospheric pressure is 101.3 kPa, the absolute pressure will be:
71.3
28
If a particle has a velocity of 4 meters per second and a kinetic energy of 144 Joules, then the mass, in kilograms of this particle must be:
18 kg
29
A condenser vacuum gauge reads 715 mm Hg when the barometer stands at 757 mm Hg. State the absolute pressure in the condenser in kN/m2 or kPa.
5.6 kPa
30
Determine the force in Newton in a piston of 465 mm2 area with a pressure of 0.172 MPa.
80
31
One piston of a hydraulic press has an area of 1 cm2. The other piston has an area of 25 cm2. If a force of 150 N is applied on the smaller piston, what will be the total force on the larger piston is both piston surfaces are the same level?
3750 N
32
If the pressure of a confined gas at a constant temperature is tripled, what will happen to the volume?
The volume will be reduced to one-third of its original value
33
The work done on air is 10.86 kJ/kg, determine the compressor power if it is receiving 272 kg/min if air.
66 HP
34
A water tank of 18 ft wide ,14 ft long and 4 ft high, calculate the pressure at the bottom of the tank.
1.733 psi
35
The pressure of 750 mm Hg in kN/m2.
100
36
A double purpose tank 18 ft wide, 24 ft long and 4 ft depth is filled with water. What is the weight of water in the tank in long tons?
49
37
Oil flow though a 16 tubes on a single cooler with a velocity of 2 m/s. The internal diameter of the tube is 30mm and oil density is 0.85 gm/ml. Find the volume flow in liters per sec.
22.62
38
A substance temperature was 620 deg R. What is the temperature in deg C?
71.11
39
Unknown volume of container gas of gas of 1 atmosphere is allowed to expand to another container of 10 m3 volume
at 500 mm Hg at constant temperature. Find the unknown volume.
6.58 m3
40
An iron block weights 7 newtons and has a volume of 200 cubic centimeters. What is the density of the block?
3565 kg/m3
41
An iron block weighs 5 Newton and has volume of 200 cm3. What is the density of the block?
2549 kg/m3
42
If air is at a pressure of 22.22 psia and at ternperature of 800°R, what is the specific volume?
13.3 ft3/lbm
43
The specific gravity of mercury is 13.55. What is the specific weight of mercury?
132.9 kN/m3
44
The equivalent weight of mass 10 kg at a location where the acceleration of gravity is 9.77 m/sec2.
97.7
45
A transportation company specializes in the shipment of pressurized gaseous materials. An order is received from 100 liters of a particular gas at STP (32°F and 1 atm). What minimum volume tank is necessary to transport the gas at 80 °F and maximum pressure of 8 atm?
14 liters
46
100 g of water are mixed with 150 g of alcohol (density 790 kg/m3). What is the specific volume of the resulting mixtures, assuming that the fluids mixed completely?
1.16 x 10‐³ cu.m/kg
47
How much does 30 lb, weigh on the moon? (9moon = 5.47 ft/s²).
5.096 lbf
48
A 10 kg block is raised vertically 3 meters. What is the change in potential energy?
294 J
49
How many cubic meters is 100 gallons of liquid?
0.3785
50
Steam turbine is receiving 1014 lbm/hr of steam, determine the horsepower output of the turbine if the work done by steam is 251 Btu/lbm
100
51
What is the resulting pressure when one pound of air at 15 psia and 200°F is heated at constant volume to 800°F
28.6 psia
52
A bicycle tire has a volume of 600 cm3. It is inflated with carbon dioxide to pressure of 551.43 kPa at 20 °C. How many grams of CO2 are contained in the tire? Rco2 = 0.18896 kJ/kg.K
5.98 g
53
The absolute pressure at the bottom of a vertical column of water is 15.5 psia. What is the height of this column?
22 in
54
A water temperature rise of 18 °F in the water cooled condenser is equivalent in °C to:
10
55
An oil storage tank contains oil with specific gravity of 0.88 and depth of 20 meters. What is the hydrostatic pressure at the bottom of the tank in kg/cm2?
1.76
56
A vertical column of water will be supported to what height by standard atmospheric pressure?
34 ft
57
The specific weight of liquid is 60 lb/ft what is the equivalent to kN/m3:
9.420
58
A cylinder weighs 150 lb. Its cross-sectional area is 40 square inches. When the cylinder stands vertically on one end, what pressure does the cylinder exert on the floor?
0.258 bar
59
What is the absolute pressure exerted on the surface of a submarine cruising 300 ft below the free surface of the sea? Assume specific gravity of sea water is 1.03.
133.9 psia
60
Air enters a nozzle steadily at 2.21 kg/m3 and 30 m/s. What is the mass flow rate through the nozzle if the inlet area of the nozzle is 80 cm2?
0.53 kg/s
61
The work required to accelerate an 800-kg car from rest to 100 km/h on a level road:
308.6 kJ
62
Assuming that there are no heat effects and no friction effects, find the speed of a 3220-lb body after it falls 778ft from rest.
224 ft/s
63
What is the flow rate through a pipe 4 inches in diameter carrying water at a velocity of 11 ft/sec?
430.8 gpm
64
If the specific weight of a liquid is 58.5 lb, per cubic foot, what is the specific volume of the liquid, cm3/g?
1.0675
65
What is the resulting pressure when one pound of air at 0.3 psig and 200 °F is heated at constant volume to 800 °F?
28.6 psia
66
A mixture of 0.4 Ibm of helium and 0.2 Ibm of oxygen is compressed polytropically from 14.7 psia and 60°F to 60 psia according to n = 1.4. Determine the final temperature, T2.
772.2 R
67
During the working stroke of an engine the heat transferred out of the system was 150 kJ/kg of working substances. The internal energy also decreased by 400 kJ/kg of working substance. Determine the work done.
250
68
Find the density of oil with a specific gravity of 1.6 in g/cm3.
1.6
69
What is the absolute pressure if the gauge pressure is reading 9 bar and the atmospheric pressure is 0.9bar?
9.9
70
The tank of an air compressor has a volume of 3 ft3 and is filled with air at a temperature of 40 °F. If a gage on the tank reads 150 psig, what is the mass of the air in the tank?
2.67 lbs
71
What is the mass of acetylene gas, V=0.94 cu.ft., R=59.35 ft.lb/lb °R, T = 90°F, P= 200 psia
0.829 lbs
72
A refrigerating system operates on the reversed Carnot Cycle. The higher temperature of the refrigerant in the sytem is 120 °F and the lower is 10 °F. The capacity is 20 tons. Neglect losses. Determine the coeffecient of performance.
4.273
73
Aluminum has a specific heat of 0.902 J/g x °C. How much heat is lost when a piece of aluminum with a mass of 23.984 g cools from a temperature of 415.0 °C to a temperature
8500 J
74
If the temperature of an air parcel is -20.5 C, and its density is 0.690 kg/m3, what is the pressure of the air parcel?
50 kPa
75
A 35.0 mL sample of gas is enclosed in a flask at 22 degrees Celsius. If the flask was placed in an ice bath at 0 degrees Celsius, what would the new gas volume be if the pressure is held constant?
32.39 mL
76
The thermal efficiency of a Carnot cycle operating between 170°C and 620°C is closest to:
50%
77
A pressure gage registers 50 psig in a region where the barometer reads 14.8 psia. Find the absolute pressure in kPa.
446.66
78
Determine the pressure exerted on a diver at 30 m below the free surface of the sea. Assume a barometric pressure of 101 kPa and the specific gravity of sea water is 1.03.
404
79
An air compressor has an inlet enthalpy of 35 Btu/lb and an exit enthalpy of 70 Btu/lb. The mass flow rate of air is 3 lb/s. If the heat loss is 466.62 Btu/min, find the work input to the compressor.
159.59 HP
80
An air compressor has an inlet enthalpy of 35 Btu/lb and an exit enthalpy of 70 Btu/lb. The mass flow rate of air is 3 lb/s. If the heat loss is 466.62 Btu/min, find the work input to the compressor.
37.51
81
A condenser vacuum gauge reads 600 mm Hg when the barometer reads 760 mm Hg. What is the absolute condenser pressure in bar?
0.213
82
Water flows in a pipe at the rate of 10 kg/s. If the velocity
of flow is 10 m/s, find the pipe diameter.
35.68 mm
83
What is the resulting pressure when one kilogram of air at
104 kPa and 98 °C is heated at constant volume to 450 °C?
202.67 kPa
84
Determine the degrees of superheat of steam at 101.325 kPa and 170 °C.
70
85
Calculate the approximate enthalpy of water at 90 °C.
376.83 kj/kg
86
A Carnot cycle operates between 30 °C and 350 °C. Find the cycle efficiency.
51.36 %
87
A Carnot cycle has a maximum temperature of 550 °F and minimum temperature of 100 °F. If the heat added is 4200 Btu/min, find the horsepower output of the engine.
44.13
88
A Camot cycle has a sink temperature of 100 °F and a cycle efficiency of 70%. Find the temperature of the heat source.
1406.70 °F
89
Fifty kilograms of cooling water per second enter the condenser at 25 °C and leaves at 50 °C. Find the heat carried away by water.
5233.75 kW
90
Determine the quality of steam in a vessel containing 2 kg of saturated vapor and 8 kg of saturated liquid.
20%
91
One kilogram of air is compressed adiabatically and in a steady-flow manner. The compression efficiency is 80% and the work done on the air is 265 kJ/kg. Compute the heat
0
92
Three-hundred kilojoules of heat flow by conduction from the outside to the inside of a cold storage in one hour. If the temperature and all other conditions are the same, what is the heat flowing through the cold storage room in two hours?
600 kj
93
Determine the specific weight of air at 760 mmHg absolute and 22 °C?
1.197
94
Two Carnot heat engine operate in series between a source at 527°C and sink at 17°C. The first engine rejects 400 KJ to the second engine. If both engines have the same efficiency. Calculate the source the temperature for the second.
208.66
95
A steam turbine receives a steam flow of 1.35 kg/s and delivers 500 KW. The heat loss from the casing is negligible. Find the change of specific enthalpy across the turbine when the velocities at the entrance and exit and the difference in elevation at the entrance and exit are negligible
-370.37 kj/kg
96
A Carnot cycle engine has a sink temperature of 45°C. Its thermal efficiency is 48.20%. The heat rejected is 742 KJ/min. Determine the power output in KW.
11.51
97
A pressure gage registers 50 psig in a region where the barometer reads 14.8 psia. Find the absolute pressure in kPa.
446.66
98
Consider 1 kg of air at 32°C that expanded by a reversible polytropic process with n = 1.25 until the pressure is halved. Determine the heat transfer. Specific heat at constant volume for air is 0.1786 kJ/kg.K.
17.02 kJ heat added
99
Fifty kilograms of cooling water per second enter the condenser at 25°C and leaves at 50°C. Find the heat carried away by water.
5233.75 KW
100
A heat engine has a thermal efficiency of 50%. How much power does the engine produce when heat is transferred at a rate of 109 kJ/hr?
139 MW
問題一覧
1
Det the specific weight of air at 760mmhg absoulte and 22C
1.197 kg/cm3
2
Find the Enthalphy of helium if its internal energy is 200 kj/kg
333.42 kj/kg
3
Compute the mass of a 2 m propane at 280 kPa and 40°C
9.47 kg
4
Find the pressure at the 100 fathom depth of water in kpag.
1,793.96
5
Find the depth in furlong of the ocean (SG = 1.03) if the pressure at the sea bed is 2,032.56 kpag.
1
6
A 1mx 1.5m cylindrical tank is full of oil with SG = 0.92. Find the force acting at the bottom of the tank in dynes.
106.33 x 10⁶
7
Find the mass of ten quartz of water
9.46 kg
8
Find the mass of carbon dioxide having a pressure of 20psia at 200°F with 10 ft³ volume
1.24 lb
9
What is the approximate value of temperature of water having enthalpy of 208 Btu/Ib?
115.55
10
Camot cycle A, B, and C are connected in series sa that the heat rejected from A will be the heat added to B and heat rejected frorn B will be added to C, each cycle operatesbetween 30°C to 400°C. If heat added to A is 1000 kw, find the work outpit of °C
111.44
11
Two kilogram of air in a figid tank changes its temperature from 32°C to 150°C. Find the work done during the process
0
12
Determine the atmospheric pressure at a location where barometric reading is 740 mm Hg and gravitational acceleration is g = 9.7 m/s?. Assume the temperature of mercury to be 10°C, at which the density is 13,670 kg/m³
97.41 kPa
13
An Ideal gas at 0.80 atmospheres and 87°C 0.450 liter. How many moles are In the sample? (R = 0.0821 liter-atm/mole-K)
0.0122
14
A certain gas at 101.325 kPa and 10°C whose volume is 2.83 m³ are compressed into a storage vessel at 0.31 m³ capacity. Before admission, the storage vessel contained the gas at a pressure and temperature of 137.8 kPa and 26°C, after admission the pressure has increased to 1171.6 kPa. What should be the final temperature of the gas in the
vessel In Kelvin?
314.2 K
15
A perfect gas has a value of R = 58.8 ft-Ib/Ib-°R and k =1.26. If 20 Btu are added to 10 Ibs of the gas at constant volume when Initial temperature is 90°F, find the final
97°F
16
Ammonia weighing 22 kgs Is confirmed inside a cylinder equipped with a piston has an initial pressure of 413 kPa at 38°C. If 3200 KJ of heat is added to the ammonia until its final pressure and temperature are 413 kPa at 100°C, respectively: what is the amount of work done by the fluid in kJ
667
17
A tank contains 90 ft of air at a pressure of 350 psig. If the air is cooled until its pressure and temperature decreases to 200 psig and 70°F, respectively, what is the decrease in Internal energy?
-6232.09 BTU
18
A large mining company was provided with a 3 m³ of compressed air tank. Air pressure in the tank drops from 700 kPa to 150 kPa while the temperature remains constant
at 28°C. What percentage has the mass of air in the tank been reduced?
78.57
19
A 4 m³/hr pump delivers water to a pressure tank. At the start, the gage reads 138 kPa unil it reads 276 kPa and then the pump was shut off. The volume of the tank is 180 liters. At 276 kPa the water occupied 2/3 of the tank volume. Determine the volume of water that can be taken out until the gage reads 138 kPa.
34.59 liters
20
Atmospheric pressure boils at 212°F. At the vacuum pressure at 24 in Hg, the temperature is 142°F. Find the boiling temperature when the pressure is increased by 40 psia from atmospheric.
449.42 F
21
Find the work posses for a Helium gas at 20 deg C.
609 kg
22
What is the hydraulic gradient of a 1 mile, 17 inches inside diameter pipe when 3300 gal/min of water flow with f = 0.003
0.00714 miles
23
Convert 750°R to °K.
416.33
24
Air Is compressed adiabatically from 30°C to 100°C. If mass of air being compressed is 5 kg. And the change in entropy
0
25
A steam condenser receives 10 kg/s of steam with an enthalpy of 2770 kJ/kg. Steam condenses into a liquid and leaves with an enthalpy of 160 kJ/kg. Cooling water passes through the condenser with temperature increases from 13°C to 24°C. Calculate the water flow rate In kg/s.
567
26
If the initial volume of an ideal gas is compressed to one-half its original volume and to twice its temperature, the pressure:
Quadruples
27
If the gage pressure of a medium is 30 kPa (vacuum) and the atmospheric pressure is 101.3 kPa, the absolute pressure will be:
71.3
28
If a particle has a velocity of 4 meters per second and a kinetic energy of 144 Joules, then the mass, in kilograms of this particle must be:
18 kg
29
A condenser vacuum gauge reads 715 mm Hg when the barometer stands at 757 mm Hg. State the absolute pressure in the condenser in kN/m2 or kPa.
5.6 kPa
30
Determine the force in Newton in a piston of 465 mm2 area with a pressure of 0.172 MPa.
80
31
One piston of a hydraulic press has an area of 1 cm2. The other piston has an area of 25 cm2. If a force of 150 N is applied on the smaller piston, what will be the total force on the larger piston is both piston surfaces are the same level?
3750 N
32
If the pressure of a confined gas at a constant temperature is tripled, what will happen to the volume?
The volume will be reduced to one-third of its original value
33
The work done on air is 10.86 kJ/kg, determine the compressor power if it is receiving 272 kg/min if air.
66 HP
34
A water tank of 18 ft wide ,14 ft long and 4 ft high, calculate the pressure at the bottom of the tank.
1.733 psi
35
The pressure of 750 mm Hg in kN/m2.
100
36
A double purpose tank 18 ft wide, 24 ft long and 4 ft depth is filled with water. What is the weight of water in the tank in long tons?
49
37
Oil flow though a 16 tubes on a single cooler with a velocity of 2 m/s. The internal diameter of the tube is 30mm and oil density is 0.85 gm/ml. Find the volume flow in liters per sec.
22.62
38
A substance temperature was 620 deg R. What is the temperature in deg C?
71.11
39
Unknown volume of container gas of gas of 1 atmosphere is allowed to expand to another container of 10 m3 volume
at 500 mm Hg at constant temperature. Find the unknown volume.
6.58 m3
40
An iron block weights 7 newtons and has a volume of 200 cubic centimeters. What is the density of the block?
3565 kg/m3
41
An iron block weighs 5 Newton and has volume of 200 cm3. What is the density of the block?
2549 kg/m3
42
If air is at a pressure of 22.22 psia and at ternperature of 800°R, what is the specific volume?
13.3 ft3/lbm
43
The specific gravity of mercury is 13.55. What is the specific weight of mercury?
132.9 kN/m3
44
The equivalent weight of mass 10 kg at a location where the acceleration of gravity is 9.77 m/sec2.
97.7
45
A transportation company specializes in the shipment of pressurized gaseous materials. An order is received from 100 liters of a particular gas at STP (32°F and 1 atm). What minimum volume tank is necessary to transport the gas at 80 °F and maximum pressure of 8 atm?
14 liters
46
100 g of water are mixed with 150 g of alcohol (density 790 kg/m3). What is the specific volume of the resulting mixtures, assuming that the fluids mixed completely?
1.16 x 10‐³ cu.m/kg
47
How much does 30 lb, weigh on the moon? (9moon = 5.47 ft/s²).
5.096 lbf
48
A 10 kg block is raised vertically 3 meters. What is the change in potential energy?
294 J
49
How many cubic meters is 100 gallons of liquid?
0.3785
50
Steam turbine is receiving 1014 lbm/hr of steam, determine the horsepower output of the turbine if the work done by steam is 251 Btu/lbm
100
51
What is the resulting pressure when one pound of air at 15 psia and 200°F is heated at constant volume to 800°F
28.6 psia
52
A bicycle tire has a volume of 600 cm3. It is inflated with carbon dioxide to pressure of 551.43 kPa at 20 °C. How many grams of CO2 are contained in the tire? Rco2 = 0.18896 kJ/kg.K
5.98 g
53
The absolute pressure at the bottom of a vertical column of water is 15.5 psia. What is the height of this column?
22 in
54
A water temperature rise of 18 °F in the water cooled condenser is equivalent in °C to:
10
55
An oil storage tank contains oil with specific gravity of 0.88 and depth of 20 meters. What is the hydrostatic pressure at the bottom of the tank in kg/cm2?
1.76
56
A vertical column of water will be supported to what height by standard atmospheric pressure?
34 ft
57
The specific weight of liquid is 60 lb/ft what is the equivalent to kN/m3:
9.420
58
A cylinder weighs 150 lb. Its cross-sectional area is 40 square inches. When the cylinder stands vertically on one end, what pressure does the cylinder exert on the floor?
0.258 bar
59
What is the absolute pressure exerted on the surface of a submarine cruising 300 ft below the free surface of the sea? Assume specific gravity of sea water is 1.03.
133.9 psia
60
Air enters a nozzle steadily at 2.21 kg/m3 and 30 m/s. What is the mass flow rate through the nozzle if the inlet area of the nozzle is 80 cm2?
0.53 kg/s
61
The work required to accelerate an 800-kg car from rest to 100 km/h on a level road:
308.6 kJ
62
Assuming that there are no heat effects and no friction effects, find the speed of a 3220-lb body after it falls 778ft from rest.
224 ft/s
63
What is the flow rate through a pipe 4 inches in diameter carrying water at a velocity of 11 ft/sec?
430.8 gpm
64
If the specific weight of a liquid is 58.5 lb, per cubic foot, what is the specific volume of the liquid, cm3/g?
1.0675
65
What is the resulting pressure when one pound of air at 0.3 psig and 200 °F is heated at constant volume to 800 °F?
28.6 psia
66
A mixture of 0.4 Ibm of helium and 0.2 Ibm of oxygen is compressed polytropically from 14.7 psia and 60°F to 60 psia according to n = 1.4. Determine the final temperature, T2.
772.2 R
67
During the working stroke of an engine the heat transferred out of the system was 150 kJ/kg of working substances. The internal energy also decreased by 400 kJ/kg of working substance. Determine the work done.
250
68
Find the density of oil with a specific gravity of 1.6 in g/cm3.
1.6
69
What is the absolute pressure if the gauge pressure is reading 9 bar and the atmospheric pressure is 0.9bar?
9.9
70
The tank of an air compressor has a volume of 3 ft3 and is filled with air at a temperature of 40 °F. If a gage on the tank reads 150 psig, what is the mass of the air in the tank?
2.67 lbs
71
What is the mass of acetylene gas, V=0.94 cu.ft., R=59.35 ft.lb/lb °R, T = 90°F, P= 200 psia
0.829 lbs
72
A refrigerating system operates on the reversed Carnot Cycle. The higher temperature of the refrigerant in the sytem is 120 °F and the lower is 10 °F. The capacity is 20 tons. Neglect losses. Determine the coeffecient of performance.
4.273
73
Aluminum has a specific heat of 0.902 J/g x °C. How much heat is lost when a piece of aluminum with a mass of 23.984 g cools from a temperature of 415.0 °C to a temperature
8500 J
74
If the temperature of an air parcel is -20.5 C, and its density is 0.690 kg/m3, what is the pressure of the air parcel?
50 kPa
75
A 35.0 mL sample of gas is enclosed in a flask at 22 degrees Celsius. If the flask was placed in an ice bath at 0 degrees Celsius, what would the new gas volume be if the pressure is held constant?
32.39 mL
76
The thermal efficiency of a Carnot cycle operating between 170°C and 620°C is closest to:
50%
77
A pressure gage registers 50 psig in a region where the barometer reads 14.8 psia. Find the absolute pressure in kPa.
446.66
78
Determine the pressure exerted on a diver at 30 m below the free surface of the sea. Assume a barometric pressure of 101 kPa and the specific gravity of sea water is 1.03.
404
79
An air compressor has an inlet enthalpy of 35 Btu/lb and an exit enthalpy of 70 Btu/lb. The mass flow rate of air is 3 lb/s. If the heat loss is 466.62 Btu/min, find the work input to the compressor.
159.59 HP
80
An air compressor has an inlet enthalpy of 35 Btu/lb and an exit enthalpy of 70 Btu/lb. The mass flow rate of air is 3 lb/s. If the heat loss is 466.62 Btu/min, find the work input to the compressor.
37.51
81
A condenser vacuum gauge reads 600 mm Hg when the barometer reads 760 mm Hg. What is the absolute condenser pressure in bar?
0.213
82
Water flows in a pipe at the rate of 10 kg/s. If the velocity
of flow is 10 m/s, find the pipe diameter.
35.68 mm
83
What is the resulting pressure when one kilogram of air at
104 kPa and 98 °C is heated at constant volume to 450 °C?
202.67 kPa
84
Determine the degrees of superheat of steam at 101.325 kPa and 170 °C.
70
85
Calculate the approximate enthalpy of water at 90 °C.
376.83 kj/kg
86
A Carnot cycle operates between 30 °C and 350 °C. Find the cycle efficiency.
51.36 %
87
A Carnot cycle has a maximum temperature of 550 °F and minimum temperature of 100 °F. If the heat added is 4200 Btu/min, find the horsepower output of the engine.
44.13
88
A Camot cycle has a sink temperature of 100 °F and a cycle efficiency of 70%. Find the temperature of the heat source.
1406.70 °F
89
Fifty kilograms of cooling water per second enter the condenser at 25 °C and leaves at 50 °C. Find the heat carried away by water.
5233.75 kW
90
Determine the quality of steam in a vessel containing 2 kg of saturated vapor and 8 kg of saturated liquid.
20%
91
One kilogram of air is compressed adiabatically and in a steady-flow manner. The compression efficiency is 80% and the work done on the air is 265 kJ/kg. Compute the heat
0
92
Three-hundred kilojoules of heat flow by conduction from the outside to the inside of a cold storage in one hour. If the temperature and all other conditions are the same, what is the heat flowing through the cold storage room in two hours?
600 kj
93
Determine the specific weight of air at 760 mmHg absolute and 22 °C?
1.197
94
Two Carnot heat engine operate in series between a source at 527°C and sink at 17°C. The first engine rejects 400 KJ to the second engine. If both engines have the same efficiency. Calculate the source the temperature for the second.
208.66
95
A steam turbine receives a steam flow of 1.35 kg/s and delivers 500 KW. The heat loss from the casing is negligible. Find the change of specific enthalpy across the turbine when the velocities at the entrance and exit and the difference in elevation at the entrance and exit are negligible
-370.37 kj/kg
96
A Carnot cycle engine has a sink temperature of 45°C. Its thermal efficiency is 48.20%. The heat rejected is 742 KJ/min. Determine the power output in KW.
11.51
97
A pressure gage registers 50 psig in a region where the barometer reads 14.8 psia. Find the absolute pressure in kPa.
446.66
98
Consider 1 kg of air at 32°C that expanded by a reversible polytropic process with n = 1.25 until the pressure is halved. Determine the heat transfer. Specific heat at constant volume for air is 0.1786 kJ/kg.K.
17.02 kJ heat added
99
Fifty kilograms of cooling water per second enter the condenser at 25°C and leaves at 50°C. Find the heat carried away by water.
5233.75 KW
100
A heat engine has a thermal efficiency of 50%. How much power does the engine produce when heat is transferred at a rate of 109 kJ/hr?
139 MW