Deck 14: Heat

Question 1

Water falls a distance of 50.0 meters. The specific heat of water is 1.00 cal/g °C. What is the increase in temperature of the water after the fall, in °C? Assume that no energy is transferred to the environment in the process.

A) 0.12
B) 1.03
C) 2.65
D) 5.33
E) 7.50

Answer 1

0.12

Question 2

A 100 g glass container contains 250 g of water at 15.0 °C. A 20.0 g piece of lead at 100 °C is added to the water in the container. What is the final temperature of the system in °C? (specific heat of water = 1.00 cal/g °C, specific heat of glass = 0.200 cal/g °C, specific heat of lead = 0.0310 cal/g °C)

A) 10.1
B) 15.2
C) 25.0
D) 31.4
E) 46.3

Answer 2

15.2

Question 3

A 100 gram aluminum container is at 15.0 °C. 150 grams of water at 80.0 °C is added to the aluminum container. What is the final temperature of the water and the aluminum? (specific heat of water = 1.00 cal/g °C, specific heat of aluminum = 0.215 cal/g °C)

A) 58.3 °C
B) 68.5 °C
C) 71.9 °C
D) 73.1 °C
E) 83.3 °C

Answer 3

71.9 °C

Question 4

A person of mass 90.0 kg walks up a flight of stairs that are 12.0 meters high. What is the required energy of the exercise in Calories?

A) 8.55
B) 7.32
C) 4.66
D) 2.53
E) 1.85

Question 5

One mole of an ideal gas at 100 °C, with a total internal energy of 15,000 J, is mixed with two moles of another ideal gas at 200 °C, with a total internal energy of 30,000 J. What is the total internal energy of the mixture?

A) 15,000 J
B) 22,500 J
C) 25,000 J
D) 45,000 J
E) 67,500 J

Question 6

A 100 g glass container is at 10.0 °C. 200 g of water at 90.0 °C is added to the glass container. What is the final temperature of the water and the glass, in °C? (specific heat of water = 1.00 cal/g °C, specific heat of glass = 0.200 cal/g °C)

A) 82.7
B) 75.0
C) 68.2
D) 50.2
E) 46.9

Question 7

If the temperature of 2.000 moles of a monatomic ideal gas is increased by 50 °C, then what is the increase in the internal energy of the gas?

A) 1,247 J
B) 1,980 J
C) 2,250 J
D) 2,750 J
E) 3,030 J

Question 8

Water has a specific heat capacity of 4,186 J/kg °C. A tank contains 500 kg of water at 10.0 °C. The water is heated to a temperature of 90.0 °C. If electricity costs $0.100 per kilowatt-hour, then what is the cost of heating the water?

A) $8.75
B) $6.22
C) $4.65
D) $3.79
E) $3.10

Question 9

A 100 g glass container contains 250 g of water at 15.0 °C. A 100 g piece of unknown material at 100 °C is added to the water in the container. The final temperature of the mixture is 19.0 °C. What is the specific heat of the unknown material in J/kg °C? (specific heat of water = 4,186 J/kg °C, specific heat of glass = 837.2 J/kg °C)

A) 245
B) 387
C) 412
D) 558
E) 674

Question 10

What is the heat needed to heat 150 g of water from 10.0 °C to 100 °C? (specific heat of water = 4,186 J/kg °C)

A) 37.2 kJ
B) 44.6 kJ
C) 56.5 kJ
D) 68.2 kJ
E) 75.1 kJ

Question 11

Which of the following is NOT included in the internal energy of a system?

A) the kinetic energy of the center of mass
B) the kinetic energy of the individual particles
C) the elastic potential energy of the individual particles
D) the chemical energy of the individual particles
E) the nuclear energy of the individual particles

Question 12

200 joules of heat flows into a 35 g sample. If the temperature increases by 10 °C, then what is the heat capacity of the sample, in J/ °C?

A) 8.0
B) 12
C) 16
D) 20
E) 32

Question 13

A 100 gram glass container contains 200 grams of water at 10 °C. A 200 gram piece of lead at 150 °C is added to the water in the container. What is the final temperature of the system? (specific heat of water = 4,186 J/kg °C, specific heat of glass = 837.2 J/kg °C, specific heat of lead = 127.7 J/kg °C)

A) 12 °C
B) 14 °C
C) 23 °C
D) 31 °C
E) 37 °C

Question 14

A person lifts 10.00 N weights a vertical distance of 50.00 cm. How many times would they have to lift the weight to use 10.00 Calories of energy?

A) 7,503
B) 4,125
C) 5,170
D) 8,370
E) 9,670

Question 15

To use 100 Calories of energy, how high would an 80.0 kg person have to climb?

A) 104 m
B) 298 m
C) 323 m
D) 486 m
E) 534 m

Question 16

What is the change in internal energy of 2.00 moles of a monatomic ideal gas that cools from 200 °C to −50 °C?

A) −500 J
B) −750 J
C) −3,742 J
D) −6,236 J
E) −13,049 J

Question 17

A 100 gram glass container contains 250 grams of water at 15.0 °C. A 200 gram piece of lead at 100 °C is added to the water in the container. What is the final temperature of the system? (specific heat of water = 4,186 J/kg °C, specific heat of glass = 837.2 J/kg °C, specific heat of lead = 127.7 J/kg °C)

A) 37 °C
B) 31 °C
C) 23 °C
D) 17 °C
E) 12 °C

Question 18

What is the change in internal energy of 2.00 moles of a monatomic ideal gas as it is heated from 0 K to 100 K?

A) 3,670 J
B) 3,250 J
C) 2,750 J
D) 2,490 J
E) 1,950 J

Question 19

A 50.0 g glass container contains 200 g of water at 20.0 °C. A 20.0 g piece of an alloy at 100 °C is added to the water in the container. The final temperature of the mixture is 24 °C. What is the specific heat of the alloy in cal/g °C? (specific heat of water = 1.00 cal/g °C, specific heat of glass = 0.200 cal/g °C)

A) 2.75
B) 1.87
C) 1.54
D) 0.852
E) 0.553

Question 20

200 joules of heat flows into a 35.0 g sample. If the temperature increases by 10.0 °C, then what is the specific heat capacity of the sample, in J/kg °C?

A) 175
B) 254
C) 375
D) 422
E) 571

Question 21

The heat of fusion for silver at 960.8 °C is 88.3 kJ/kg and the specific heat of silver is 0.235 kJ/kg °C. What is the energy needed to melt 100 grams of silver starting at 0 °C?

A) 40.5 kJ
B) 31.4 kJ
C) 25.4 kJ
D) 19.5 kJ
E) 13.7 kJ

Question 22

A 2,000 kg car is traveling at 20.0 m/s and then puts on the brakes and comes to a complete stop. The heat generated at the brakes due to stopping heats up the brakes. The mass of the brake system is 20.0 kg and it has a specific heat of 0.200 kcal/kg °C. What is the increase in the temperature of the brakes?

A) 75.3 °C
B) 53.1 °C
C) 23.9 °C
D) 18.9 °C
E) 12.4 °C

Question 23

The heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the energy needed to vaporize 100 grams of ice at starting at 0 °C?

A) 33.37 kJ
B) 41.86 kJ
C) 225.6 kJ
D) 259.0 kJ
E) 300.8 kJ

Question 24

The heat of fusion for gold at 1,063 °C is 66.6 kJ/kg and the specific heat of gold is 0.128 kJ/kg °C. What is the energy needed to melt 100 grams of gold starting at 0 °C?

A) 20.3 kJ
B) 17.8 kJ
C) 12.3 kJ
D) 9.50 kJ
E) 7.50 kJ

Question 25

The heat of fusion for lead at 327 °C is 22.9 kJ/kg and the specific heat of solid lead is 0.130 kJ/kg °C, the specific heat of liquid lead is 0.0900 kJ/kg °C, and the heat of vaporization of lead at 1,620 °C is 871 kJ/kg. What is the energy needed to vaporize 100 grams of lead starting at 0 °C?

A) 105 kJ
B) 189 kJ
C) 176 kJ
D) 156 kJ
E) 147 kJ

Question 26

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0°C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 20.0 grams of ice at −15.0 °C is mixed with 5.00 grams of steam at 100 °C?

A) 44.1 °C
B) 48.9 °C
C) 52.7 °C
D) 58.0 °C
E) 65.2 °C

Question 27

A 2,000 kg car is traveling at 15.0 m/s down a long mountain grade of 2.00%. The mountain road is 5.0 km long. The heat generated at the brakes due to friction heats up the brakes. The mass of the brake system is 20.0 kg and it has a specific heat of 0.200 kcal/kg °C. What is the increase in the temperature of the brakes?

A) 43 °C
B) 54 °C
C) 83 °C
D) 95 °C
E) 117 °C

Question 28

A 2,000 kg car is traveling at 20.0 m/s down a long mountain grade of 1.00%. The mountain road is 3.00 km long. The heat generated at the brakes due to friction heats up the brakes. The mass of the brake system is 20.0 kg and it has a specific heat of 0.200 kcal/kg °C. What is the increase in the temperature of the brakes?

A) 22.3 °C
B) 35.1 °C
C) 40.2 °C
D) 45.2 °C
E) 53.6 °C

Question 29

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 5.00 grams of ice at −15.0 °C is mixed with 40.0 grams of water at 75.0 °C?

A) 57.0 °C
B) 28.3 °C
C) 20.9 °C
D) 18.6 °C
E) 16.1 °C

Question 30

A sample of helium has a volume of 2.00 liters, a temperature of 20.0 °C, and a pressure of 2.50 atmospheres. What is the energy needed to heat the sample of helium gas from 20.0 °C to 95.0 °C at constant volume?

A) 88.0 J
B) 137 J
C) 194 J
D) 207 J
E) 476 J

Question 31

What is the heat needed to heat 16.0 grams of helium gas at constant volume from 20.0 °C to 85.0 °C?

A) 4.23 kJ
B) 3.24 kJ
C) 2.02 kJ
D) 1.95 kJ
E) 0.650 kJ

Question 32

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 10.0 grams of ice at −15 °C is mixed with 40.0 grams of water at 75 °C?

A) 59.5 °C
B) 57.2 °C
C) 53.6 °C
D) 48.9 °C
E) 42.6 °C

Question 33

A 2,000 kg car is traveling at 40.0 m/s and then puts on the brakes and comes to a complete stop. The heat generated at the brakes due to stopping heats up the brakes. The mass of the brake system is 20.0 kg and it has a specific heat of 0.200 kcal/kg °C. What is the increase in the temperature of the brakes?

A) 66.6 °C
B) 75.4 °C
C) 87.5 °C
D) 95.6 °C
E) 117 °C

Question 34

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0°C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 30.0 grams of ice at −15.0 °C is mixed with 8.00 grams of steam at 100 °C?

A) 65.6 °C
B) 60.2 °C
C) 56.2 °C
D) 50.1 °C
E) 45.2 °C

Question 35

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, the heat of vaporization of water at 100 °C is 2,256 kJ/kg, and the specific heat of steam is 2.020 kJ/kg °C. What is the final equilibrium temperature when 40.0 grams of ice at 0 °C is mixed with 5.00 grams of steam at 120 °C?

A) 3.01 °C
B) 2.65 °C
C) 1.21 °C
D) 1.07 °C
E) 0.90 °C

Question 36

The molar specific heat of a diatomic ideal gas at constant volume is Cv = 5/2 R. What is the heat needed to heat 28.00 g of nitrogen gas from 20.00 °C to 85.00 °C?

A) 1,350 J
B) 2,890 J
C) 1,753 J
D) 1,540 J
E) 1,443 J

Question 37

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 10.0 grams of ice at −15.0 °C is mixed with 3.00 grams of steam at 100 °C?

A) 60.2 °C
B) 65.0 °C
C) 70.2 °C
D) 76.4 °C
E) 80.3 °C

Question 38

The heat of vaporization of water at 100.0 °C is 2,256 kJ/kg. What is the heat of vaporization of water in cal/g?

A) 365.3
B) 418.6
C) 497.2
D) 538.9
E) 684.1

Question 39

The heat of fusion for lead at 327.0 °C is 22.9 kJ/kg and the specific heat of lead is 0.130 kJ/kg °C. What is the energy needed to melt 100 grams of lead starting at 0 °C?

A) 3.56 kJ
B) 4.23 kJ
C) 6.54 kJ
D) 7.02 kJ
E) 7.76 kJ

Question 40

The heat of fusion for ice at 0 °C is 333.7 kJ/kg. What is the energy needed to melt 100 grams of ice at 0.00 °C?

A) 39.4 kJ
B) 12.7 kJ
C) 17.5 kJ
D) 25.5 kJ
E) 33.4 kJ

Question 41

A Styrofoam cooler has a surface area of 2,700 cm² and a wall thickness of 3.00 cm. Styrofoam has a thermal conductivity of 0.010 W/m °C. A 2.00 kg block of ice is placed inside the cooler that has a temperature inside of 2°C. When the temperature outside is 30.0°C, the ice lasts for 8.00 hours. If the temperature outside becomes 20.0°C, then how long will the ice last? Ignore the effect of the air inside the cooler.

A) 20.3 hr
B) 18.5 hr
C) 12.4 hr
D) 10.1 hr
E) 8.5 hr

Question 42

The specific heat of ice is 2.100 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100.0 °C is 2,256 kJ/kg. What is the final equilibrium temperature when 10.00 grams of ice at −15 °C is mixed with 3.000 grams of steam at 100 °C?

A) 87.21 °C
B) 85.32 °C
C) 80.34 °C
D) 82.56 °C
E) 78.45 °C

Question 43

The specific heat of ice is 2.100 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, the heat of vaporization of water at 100.0 °C is 2,256 kJ/kg, and the specific heat of steam is 2.020 kJ/kg °C. What is the final equilibrium temperature when 20.00 grams of ice at −15.0 °C is mixed with 5.000 grams of steam at 120.0 °C?

A) 59.92 °C
B) 56.03 °C
C) 52.76 °C
D) 49.34 °C
E) 45.67 °C

Question 44

A Styrofoam cooler has a surface area of 2,700 cm² and a wall thickness of 3.0 cm. Styrofoam has a thermal conductivity of 0.010 W/m °C. A 2.0 kg block of ice is placed inside the cooler that has a temperature inside of 2.0 °C. If the heat of fusion for ice is 333.7 kJ/kg and the temperature outside is 35.0 °C, then how long will the ice last? Ignore the effect of the air inside the cooler.

A) 74 hours
B) 62 hours
C) 55 hours
D) 42 hours
E) 24 hours

Question 45

The specific heat of water is 1.000 cal/(g·°C). What is the specific heat of water in SI units?

A) 2,124 J/(kg·K)
B) 2,765 J/(kg·K)
C) 3,417 J/(kg·K)
D) 3,764 J/(kg·K)
E) 4,186 J/(kg·K)

Question 46

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, the heat of vaporization of water at 100 °C is 2,256 kJ/kg, and the specific heat of steam is 2.020 kJ/kg °C. What is the final equilibrium temperature when 40.0 grams of ice at 0 °C is mixed with 8.00 grams of steam at 120 °C?

A) 50.22 °C
B) 41.67 °C
C) 38.76 °C
D) 32.55 °C
E) 25.67 °C

Question 47

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, the heat of vaporization of water at 100 °C is 2,256 kJ/kg, and the specific heat of steam is 2.020 kJ/kg °C. What is the final equilibrium temperature when 10.0 grams of ice at −15.0 °C is mixed with 2.00 grams of steam at 120 °C?

A) 40.1 °C
B) 39.5 °C
C) 37.2 °C
D) 35.4 °C
E) 33.2 °C

Question 48

A brass rod with a length of 20.0 cm is placed end to end with an aluminum rod with a length of 20.0 cm, and this system is placed between a hot temperature of 100 °C and a cold temperature of 10.0 °C. The thermal conductivities of the brass and the aluminum are 100 W/m °C and 230 W/m °C, respectively. The rods have the same cross-sectional area of 25.0 cm². What is the heat flow from the hot temperature to the cold temperature?

A) 78.4 W
B) 70.2 W
C) 65.3 W
D) 61.5 W
E) 55.5 W

Question 49

A brass rod is placed between two temperature sources so that heat can flow between them. One temperature is 80 °C and the other temperature is 20 °C. The length of the rod is 50.0 cm and the cross-sectional area is 15.0 cm². If the thermal conductivity for brass is 100 W/m °C, then what is the heat flow between the hot temperature and the cold temperature?

A) 7.5 W
B) 8.2 W
C) 9.4 W
D) 12 W
E) 18 W

Question 50

A brass rod with a length of 30.0 cm is placed side by side with an aluminum rod with a length of 30.0 cm, and this system is placed between a hot temperature of 100°C and a cold temperature of 10.0°C. The thermal conductivities of the brass and the aluminum are 100 W/m °C and 230 W/m °C, respectively. The brass rod has a cross-sectional area of 20.0 cm², and the aluminum rod has a cross-sectional area of 30.0 cm². What is the rate of heat flow from the hot temperature to the cold temperature?

A) 542 W
B) 26.7 W
C) 54.2 W
D) 267 W

Question 51

The specific heat of ice is 2.10 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, the heat of vaporization of water at 100 °C is 2,256 kJ/kg, and the specific heat of steam is 2.020 kJ/kg °C. What is the final equilibrium temperature when 30.0 grams of ice at 0 °C is mixed with 4.00 grams of steam at 120 °C?

A) 3.02 °C
B) 5.97 °C
C) 8.77 °C
D) 10.2 °C
E) 18.4 °C

Question 52

A brass plate with a thickness of 1.00 cm is placed over a copper plate with a thickness of 2.00 cm. Take the thermal conductivity of brass to be 100 W/m °C and that of copper to be 400 W/m °C. What is the effective thermal conductivity for the brass-copper layer?

A) 150 W/m °C
B) 200 W/m °C
C) 250 W/m °C
D) 300 W/m °C
E) 350 W/m °C

Question 53

The specific heat of ice is 2.100 kJ/kg °C, the heat of fusion for ice at 0 °C is 333.7 kJ/kg, the specific heat of water 4.186 kJ/kg °C, and the heat of vaporization of water at 100 °C is 2,256 kJ/k. What is the final equilibrium temperature when 10.00 grams of ice at −15.00 °C is mixed with 2.00 grams of steam at 100.0 °C?

A) 27.54 °C
B) 33.79 °C
C) 40.12 °C
D) 45.71 °C
E) 53.53 °C

Question 54

The specific heat of steam is 2,020 J/kg K in SI units. What is the value of the specific heat of steam in cal/g °C?

A) 1.000
B) 0.8765
C) 0.6812
D) 0.4826
E) 0.2563

Question 55

A student is sleeping under a small goose-down comforter that has thermal conductivity of 0.025 W/m °C. The thickness of the down comforter is 5.0 cm and the area of the comforter is 2.0 m². If the temperature difference between inside of the comforter and the outside of the comforter 40 °C, then what is the rate of heat flow through the comforter?

A) 10 W
B) 20 W
C) 30 W
D) 40 W
E) 50 W

Question 56

A 100 gram glass container contains 200 grams of water and 5 grams of ice all at 0 °C. A 200 gram piece of lead at 100 °C is added to the water and ice in the container. What is the final temperature of the system? (specific heat of ice = 2,000 J/kg °C , specific heat of water = 4,186 J/kg °C, heat of fusion of water = 333.7 kJ/kg, specific heat of glass = 837.2 J/kg °C, specific heat of lead = 127.7 J/kg °C)

A) 5.33 °C
B) 4.87 °C
C) 3.65 °C
D) 2.19 °C
E) 0.915 °C

Question 57

A 100 gram glass container contains 200 grams of water and 10 grams of ice all at 0 °C. A 200 gram piece of lead at 100 °C is added to the water and ice in the container. What is the final temperature of the system? (specific heat of ice = 2,000 J/kg °C, specific heat of water = 4,186 J/kg °C, heat of fusion of water = 333.7 kJ/kg, specific heat of glass = 837.2 J/kg °C, specific heat of lead = 127.7 J/kg °C)

A) 0 °C
B) 1.85 °C
C) 2.86 °C
D) 3.43 °C
E) 4.01 °C

Question 58

A brass rod with a length of 10.0 cm is placed end to end with an aluminum rod with a length of 30.0 cm, and this system is placed between a hot temperature of 100 °C and a cold temperature of 10.0 °C. The thermal conductivities of the brass and the aluminum are 100 W/m °C and 230 W/m °C, respectively. The rods have the same cross-sectional area of 20.0 cm². What is the heat flow from the hot temperature to the cold temperature?

A) 55.3 W
B) 65.3 W
C) 70.3 W
D) 78.1 W
E) 85.3 W

Question 59

The inside temperature of a house is 65 °F. When the temperature outside the house is 35 °F, the furnace supplies 100 joules per hour to keep the inside of the house warm. If the temperature outside the house increases to 50 °F, then what is the fuel consumption of the furnace? Assume the house loses heat through conduction only.

A) 38 joules per hour
B) 42 joules per hour
C) 50 joules per hour
D) 56 joules per hour
E) 61 joules per hour

Question 60

A metal rod is placed between two temperature sources so that heat can flow between them. One temperature is 90.0 °C and the other temperature is 25.0 °C. The length of the rod is 30.0 cm and the cross-sectional area is 10.0 cm². If 15.0 watts of heat flows between the hot temperature and the cold temperature, then what is the thermal conductivity for the metal?

A) 69.2 W/(m·°C)
B) 58.2 W/(m·°C)
C) 50.4 W/(m·°C)
D) 46.3 W/(m·°C)
E) 44.2 W/(m·°C)

Question 61

Radiant energy from the Sun reaches the Earth at a rate of 1.70 × 10¹⁷ W. When 30% of the radiant energy is reflected and 70% absorbed, the average temperature of the Earth's atmosphere is 253 K. If the atmosphere absorbed 100% of the solar radiant energy, then what would be the average temperature of the Earth's atmosphere?

A) 274 K
B) 275 K
C) 276 K
D) 277 K
E) 278 K

Question 62

What form of convection causes the onshore sea breeze in the day?

A) natural convection of air falling over the cooling land
B) forced convection air or forced convection of water
C) forced convection of water
D) natural convection of air rising over the warming land

Question 63

The intensity of solar radiation reaching the Earth is 1,340 W/m². If the sun has a radius of 7.000 × 10⁸ m, is a perfect radiator and is located 1.500 × 10¹¹ m from the Earth, then what is the temperature of the sun?

A) 6,430 K
B) 5,740 K
C) 4,230 K
D) 3,670 K
E) 3,210 K

Question 64

A wood-burning stove in a cabin in the woods has a surface area of 0.100 m². If the stove radiates heat like a perfect blackbody with a temperature of 150 °C, then what is the energy per second that the stoves radiates?

A) 432 W
B) 658 W
C) 287 W
D) 182 W
E) 212 W

Question 65

The intensity of solar radiation reaching the Earth is 1,340 W/m² when the temperature of the Sun is 5,800 K. If the temperature of the Sun decreased by 10.0%, then what would be the intensity of solar radiation reaching the Earth?

A) 879 W/m²
B) 752 W/m²
C) 667 W/m²
D) 610 W/m²
E) 578 W/m²

Question 66

If the temperature of the sun is 5,800 K, then what is wavelength at which the blackbody radiation is a maximum?

A) 402 nm
B) 465 nm
C) 500 nm
D) 575 nm
E) 625 nm

Question 67

The outer surface of a wood-burning stove in a cabin is at a temperature of 150 °C. What is the wavelength at which the blackbody radiation is a maximum?

A) 3.64 μm
B) 4.02 μm
C) 4.57 μm
D) 5.25 μm
E) 6.85 μm

Question 68

Radiant energy from the Sun reaches the Earth at a rate of 1.70 × 10¹⁷ W. When 30.0% of the radiant energy is reflected and 70.0% absorbed, the average temperature of the Earth's atmosphere is 253 K or −20 °C. If the atmosphere reflected 40.0% and absorbed 60.0% of the solar radiant energy, then what is the average temperature of the Earth's atmosphere?

A) −26 °C
B) −27 °C
C) −28 °C
D) −29 °C
E) −30 °C

Question 69

The intensity of solar radiation reaching the Earth is 1,340 W/m² when the temperature of the Sun is 5,800 K. If the temperature of the Sun increased by 10.00%, then what would be the intensity of solar radiation reaching the earth?

A) 1,492 W/m²
B) 1,632 W/m²
C) 1,828 W/m²
D) 1,962 W/m²
E) 2,004 W/m²

Question 70

What type of heat transfer is used to carry heat from the house furnace to the living room of most houses?

A) natural convection of air falling over the cooling land
B) forced convection of air or forced convection of water
C) radiation
D) natural convection of air rising over the warming land

Question 71

What form of convection causes the offshore sea breeze in the evening?

A) natural convection of air falling over the cooling land
B) forced convection air or forced convection of water
C) forced convection of water
D) natural convection of air rising over the warming land

Question 72

A jogger runs a kilometer in 8.30 minutes in still, dry air at a temperature of 25.0 °C. Her skin has a temperature of 35.0 °C and an exposed area of 1.00 m². If the convective coefficient is 22.0 W/m² °C, then what is the rate of heat flow due to convection from her skin to the air?

A) 95.7 W
B) 102 W
C) 186 W
D) 220 W
E) 285 W

Question 73

A rigid cubic box, 15 cm on a side, is filled with nitrogen gas (N₂) at standard temperature and pressure (0 °C and 1 atm). If 185 J of heat is added to the box, what is the final temperature of the gas?

A) 69 °C
B) 88 °C
C) 150 °C
D) 50 °C
E) 59 °C

Question 74

A brass rod with a length of 20.0 cm is placed side by side with an aluminum rod with a length of 20.0 cm, and this system is placed between a hot temperature of 150 °C and a cold temperature of −10.0 °C. The thermal conductivities of the brass and the aluminum are 100 W/m °C and 230 W/m °C, respectively. The rods have the same cross-sectional area of 20.0 cm². What is the rate of heat flow from the hot temperature to the cold temperature?

A) 683 W
B) 528 W
C) 52.8 W
D) 68.3 W

Question 75

A food Calorie is a kilocalorie in SI units. What would be the speed of a 1,000 kg car traveling such that its kinetic energy is equal to the energy contained in one 250-Calorie jelly doughnut?

A) 46 m/s
B) 65 m/s
C) 32 m/s
D) 22 m/s

Question 76

Radiant energy from the Sun reaches the Earth at a rate of 1.70 × 10¹⁷ W. When 30.0% of the radiant energy is reflected and 70.0% absorbed, the average temperature of the Earth's atmosphere is 253 K or −20 °C. If the atmosphere reflected 20.0% and absorbed 80.0% of the solar radiant energy, then what would be the average temperature of the Earth's atmosphere?

A) −10 °C
B) −11 °C
C) −12 °C
D) −14 °C
E) −17 °C

Question 77

A tungsten light bulb is glowing with blackbody radiation whose maximum occurs at a wavelength of 700.0 nm. What is the temperature of the tungsten element?

A) 3,750 K
B) 4,140 K
C) 4,250 K
D) 4,790 K
E) 5,030 K

Question 78

A concrete wall is 15.0 cm thick and has an area of 10.0 m². A layer of wood that is 2.50 cm thick is placed over the wall to reduce the loss of heat by thermal conduction. The thermal conductivity of concrete is 1.70 W/m °C and the thermal conductivity of wood is 0.0400 W/m °C. What is the effective thermal conductivity of the wood-on-concrete system?

A) 0.245 W/m °C
B) 1.22 W/m °C
C) 1.65 W/m °C
D) 2.02 W/m °C
E) 2.34 W/m °C

Question 79

Which type of heat transfer is used in most automobile engines to carry excess heat away from the hot engine?

A) natural convection of air falling over the cooling land
B) radiation
C) forced convection of water
D) natural convection of air rising over the warming land

Question 80

The heating element of an electric stove is glowing. The color of the hot stove element is red, with a blackbody radiation spectrum with a maximum at a wavelength of 1.000 micron. What is the temperature of the stove element?

A) 2,276 K
B) 2,537 K
C) 2,898 K
D) 3,137 K
E) 3,375 K