Deck 16: Temperature and Heat

Question 1

FIGURE 16-2
Consider a flat steel plate with a hole through its center as shown in Figure 16-2. When the plate's temperature is increased, the hole will

A) expand only if it takes up more than half the plate's surface area.
B) contract if it takes up less than half the plate's surface area.
C) always contract.
D) always expand.
E) remain the same size.

Answer 1

always expand.

Question 2

When you sit by a campfire, by what method of heat transfer are you primarily being warmed?

Answer 2

by radiation

Question 3

FIGURE 16-1
Refer to Figure 16-1. A bimetallic strip, consisting of metal G on the top and metal H on the bottom, is rigidly attached to a wall at the left. The coefficient of linear thermal expansion for metal G is greater than that of metal H. If the strip is uniformly heated, it will

A) curve upward.
B) curve downward.
C) remain horizontal, but get longer.
D) remain horizontal, but get shorter.
E) bend in the middle.

Answer 3

curve downward.

Question 4

Describe the anomalous thermal expansion property of water and its significance.

Question 5

State the Zeroth Law of Thermodynamics.

Question 6

What is the ratio of the pressure that a constant-volume gas thermometer registers at the boiling point of water to the pressure it registers at the freezing point?

A) 1.00
B) 1.24
C) 1.32
D) 1.37
E) 1.80

Question 7

Does it make sense to say that an object has twice as much heat as another?
Why?

Question 8

You are removing a pie from a 350°F oven, and while you need to protect your hands from the pie pan, the backs of your hands and your wrists and forearms are unprotected, yet they don't get burned. Why?

Question 9

You are given a piece of pie straight out of the oven, so the crust and the filling are at the same temperature. You sample a piece of crust with no problem, but when you put a piece of filling in your mouth, you burn your tongue. Why?

Question 10

Heat is energy that is transferred between objects that are in thermal contact because of a temperature difference.

Question 11

If a thermometer measures the temperature of two objects as being equal, you can conclude that if the objects are placed in thermal contact, no heat will flow between them.

Question 12

When a bimetallic strip is cooled, the strip will bend toward the side

A) with the larger coefficient of linear expansion.
B) with the smaller coefficient of linear expansion.
C) with the higher temperature.
D) with the lower temperature.

Question 13

Radiative heat transfer requires a fluid to mediate the energy transfer.

Question 14

By what method of heat transfer does a microwave oven transfer heat to the food being cooked?

Question 15

The amount of heat that flows through a rod whose ends are held at different temperatures is proportional to the length of the rod.

Question 16

When a bimetallic strip is heated, the strip will bend toward the side

A) with the larger coefficient of linear expansion.
B) with the smaller coefficient of linear expansion.
C) with the higher temperature.
D) with the lower temperature.

Question 17

The amount of heat that flows through a rod whose ends are held at different temperatures is proportional to the area of the rod.

Question 18

Conductive heat transfer can only occur if solids mediate the energy transfer.

Question 19

Convective heat transfer can only occur if fluids mediate the energy transfer.

Question 20

If a thermometer measures the temperature of two objects as being equal, you can conclude that the objects will be in thermal equilibrium if they are brought into thermal contact.

Question 21

FIGURE 16-3
Two metal rods are to be used to conduct heat from a region at 100°C to a region at 0°C as shown in Figure 16-3. The rods can be placed in parallel, as shown on the left, or in series, as on the right. The heat conducted in the series arrangement is

A) greater than the heat conducted with the rods in parallel.
B) the same as the heat conducted with the rods in parallel.
C) less than the heat conducted with the rods in parallel.
D) impossible to compare with the heat conducted with the rods in parallel.

Question 22

FIGURE 16-3
If the absolute temperature of an object is doubled, the thermal power radiated per unit surface area of this object will (assuming that its emissivity is not affected by the temperature change)

A) increase by a factor of 2.
B) increase by a factor of 4.
C) increase by a factor of 8.
D) increase by a factor of 16.
E) increase by a factor of 32.

Question 23

Object 1 has three times the specific heat capacity and four times the mass of Object 2. The two objects are given the same amount of heat. If the temperature of Object 1 changes by an amount ΔT, the change in temperature of Object 2 will be

A) ΔT.
B) ΔT.
C) ΔT.
D) 6ΔT.
E) 12ΔT.

Question 24

The process whereby heat flows by the mass movement of molecules from one place to another is referred to as

A) conduction.
B) convection.
C) radiation.
D) inversion.
E) evaporation.

Question 25

FIGURE 16-3
If the absolute temperature of an object is tripled, the thermal power radiated per unit surface area of this object will (assuming that its emissivity is not affected by the temperature change)

A) increase by a factor of 3.
B) increase by a factor of 9.
C) increase by a factor of 18.
D) increase by a factor of 27.
E) increase by a factor of 81.

Question 26

If you double the thickness of a wall built from a homogeneous material, the rate of heat loss for a given temperature difference across the thickness will

A) become one-half its original value.
B) double.
C) become one-fourth its original value.
D) quadruple.
E) become one-eighth its original value.

Question 27

The type of heat transfer that occurs between the radiator of a car and the atmosphere, when the car is in motion, is principally

A) convective.
B) conductive.
C) radiative.
D) countercurrent.
E) evaporation.

Question 28

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper; the aluminum and the copper are in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater magnitude gain or loss of heat during the time the system takes to reach thermal equilibrium?

A) the aluminum
B) the copper
C) neither; both experience the same size gain or loss of heat
D) it is impossible to tell without knowing the masses
E) it is impossible to tell without knowing the volumes

Question 29

Object 1 has three times the specific heat capacity and four times the mass of Object 2. The two objects are heated from the same initial temperature, T₀, to the same final temperature T_f. You determine that the amount of heat gained by Object 1 is Q. The amount of heat absorbed by Object 2 will be

A) 12Q.
B) 6Q.
C) Q.
D) Q.
E) Q.

Question 30

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper; the aluminum and the copper are in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater temperature change during the time the system takes to reach thermal equilibrium?

A) the copper
B) the aluminum
C) neither; both experience the same size temperature change
D) it is impossible to tell without knowing the masses
E) it is impossible to tell without knowing the volumes

Question 31

The type of heat transfer that occurs between a heating lamp and the food that it is keeping warm is

A) convective.
B) conductive.
C) radiative.
D) countercurrent.
E) evaporation.

Question 32

Convection can occur

A) only in solids.
B) only in liquids.
C) only in gases.
D) only in liquids and gases.
E) in solids, liquids, and gases.

Question 33

When you walk barefoot in a room, the floor feels cooler walking on a tile floor as compared to a wooden floor because

A) tile has a smaller specific heat than wood.
B) tile has a larger specific heat than wood.
C) tile has a smaller thermal conductivity than wood.
D) tile has a larger thermal conductivity than wood.
E) none of the above

Question 34

The type of heat transfer that occurs between a stove and a pot placed on it is

A) convective.
B) conductive.
C) radiative.
D) countercurrent.
E) evaporation.

Question 35

You walk barefoot in your house and cross from the carpeted living room to the tiled-floor kitchen. The tile floor always feels

A) cooler than the carpet.
B) the same temperature as the carpet.
C) warmer than the carpet.
D) warmer than the carpet in summer but cooler in winter.
E) cooler than the carpet in summer but warmer in winter.

Question 36

The type of heat transfer that occurs between warm food and the air in the room is principally

A) convective.
B) conductive.
C) radiative.
D) countercurrent.
E) evaporation.

Question 37

An industrial fabrication process stamps out thin metal pieces, each in the shape of a square with a circular hole in the middle, from a large thin sheet. These pieces are mounted in a large machine. As these pieces heat up during regular machine operation, the diameter of the circular hole will

A) decrease.
B) stay the same.
C) increase.
D) behave unpredictably causing the machine to malfunction.

Question 38

FIGURE 16-2
Consider a flat steel plate with a hole through its center as shown in Figure 16-2. When the plate's temperature is decreased, the hole will

A) contract only if it takes up more than half the plate's surface area.
B) expand if it takes up less than half the plate's surface area.
C) contract.
D) expand.
E) remain the same size.

Question 39

The process whereby heat flows by means of molecular collisions is referred to as

A) conduction.
B) convection.
C) radiation.
D) inversion.
E) evaporation.

Question 40

Two metal spheres are made of the same material and have the same diameter, but one is solid and the other is hollow. If their temperature is increased by the same amount,

A) the solid sphere becomes bigger than the hollow one.
B) the hollow sphere becomes bigger than the solid one.
C) the two spheres remain of equal size.
D) the solid sphere becomes heavier and the hollow one lighter.
E) the solid sphere becomes lighter and the hollow one heavier.

Question 41

Platinum melts at 3215°F. What is the corresponding temperature in the Kelvin scale?

A) 2041 K
B) 2135 K
C) 2207 K
D) 2296 K
E) 3215 K

Question 42

The thermal conductivity of concrete is 0.80 W/m-C° and the thermal conductivity of wood is 0.10 W/m-C°. How thick would a solid concrete wall have to be in order to have the same rate of flow through it as an 8.0 cm thick wall made of solid wood?
(Assume both walls have the same surface area.)

Question 43

Ten meter long steel railroad rails are laid end to end, with no space between, on a hot day when the temperature is 115.°F. Six months later the temperature has dropped to -2.°F. How much space now exists between each rail?
[ linear expansion coef. for steel is 12. × 10^-6 C°^-1]

Question 44

FIGURE 16-3
The process whereby heat flows in the absence of any medium is referred to as

A) conduction.
B) convection.
C) radiation.
D) inversion.
E) evaporation.

Question 45

A wall consists of 2 layers of material:
brick in front of an equal thickness of wood. If the respective thermal conductivities of the brick and wood are 1.3 J/m-s-C and 0.15 J/m-s-C, how does the temperature gradient across the wood compare to the gradient across the brick?

Question 46

The coefficient of linear expansion of lead is 29 × 10^-6 K^-1. What change in temperature will cause a 10-m long lead bar to change in length by 3.0 mm?

A) 5.0 K
B) 10 K
C) 15 K
D) 20 K
E) 25 K

Question 47

The temperature in a room is 77°F. What is the corresponding temperature in the Celsius scale?

A) 81°C
B) 77°C
C) 43°C
D) 25°C
E) 18°C

Question 48

The weather outside is frightful. The temperature is -22°F. What is the corresponding temperature in the Celsius scale?

A) -35°C
B) -30°C
C) -22°C
D) -20°C
E) -12°C

Question 49

0.45 kg of a metal at 90.°C is added to 0.40 kg of water at 20.0°C.
(a) If the final temperature of the mixture is 26.°C, what is the specific heat of the metal?
(b) If the water container has a significant heat capacity, will this increase or decrease the metal specific heat determined in part (a) given the same data?

Question 50

A steel cable spanning a river is 200.000 m long when the temperature is 20.°C. What will be its length when the temperature drops to 0°C?
(The coefficient of thermal expansion of steel is 12. × 10^-6K^-1.)

Question 51

Gas in a constant-volume gas thermometer registers a pressure of 95.0 kPa at 100°C. Assuming ideal behavior, what is the temperature of this gas when the pressure is 190 kPa?

A) 546°C
B) 527°C
C) 491°C
D) 473°C
E) 200°C

Question 52

Gas in a constant-volume gas thermometer registers a pressure of 75.0 kPa at 0°C. Assuming ideal behavior, what is the pressure of this gas at 200°C?

A) 120 kPa
B) 130 kPa
C) 140 kPa
D) 150 kPa
E) 160 kPa

Question 53

In an electric furnace used for refining steel, the temperature is monitored by measuring the radiant power emitted through a small hole of area 0.50 cm². The furnace acts like a blackbody radiator. If it is to be maintained at a temperature of 1650°C, at what level should the power radiated through the hole be maintained?

Question 54

At what rate is the human body radiating energy when it is at 33°C?
Take the body surface area to be 1.4 m², and approximate the body as a black body.

Question 55

At what temperature are the numerical readings on the Fahrenheit and Celsius scales the same?

Question 56

A person tries to heat up her bath water by adding 5.0 L of water at 80°C to 60 L of water at 30°C. What is the final temperature of the water?

Question 57

The coefficient of linear expansion of steel is 12 × 10^-6 K^-1. What is the change in length of a 25-m steel bridge span when it undergoes a temperature change of 40 K?

A) 1.2 cm
B) 1.4 cm
C) 1.6 cm
D) 1.8 cm
E) 2.0 cm

Question 58

In grinding a steel knife blade (specific heat = 0.11 cal/g-C°), the metal can get as hot as 400.°C. If the blade has a mass of 80. g, what is the minimum amount of water needed at 20°C if the water is not to rise above the boiling point when the hot blade is quenched in it?

Question 59

Gallium boils at 2205°C. What is the corresponding temperature in the Fahrenheit scale?

A) 2205°F
B) 3805°F
C) 4001°F
D) 5223°F
E) 5548°F

Question 60

Nitrogen boils at -196°C. What is the corresponding temperature in the Fahrenheit scale?

A) -315°F
B) -196°F
C) -346°F
D) -290°F
E) -321°F

Question 61

330 g of water at 45°C are poured into an 855 g aluminum container with an initial temperature of 10°C. The specific heat of aluminum is 900 J/(kg·K). What is the final temperature of the system, assuming no heat is exchanged with the surroundings?

A) 28°C
B) 32°C
C) 31°C
D) 33°C
E) 35°C

Question 62

A 5.00-g lead bullet moving at 440 m/s penetrates a wood block and comes to rest inside the block. If half of its kinetic energy goes into heating the bullet, what is the bullet's change in temperature? The specific heat of lead is 128 J/(kg·K).

A) 94.0 K
B) 110 K
C) 126 K
D) 278 K
E) 378 K

Question 63

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1. A block of copper 30 cm wide, 45 cm long, and 10 cm thick is heated from 0°C to 100°C What is the change in the volume of the block?

A) 2.3 × 10^-5 m³
B) 4.6 × 10^-5 m³
C) 5.2 × 10^-5 m³
D) 6.9 × 10^-5 m³
E) 13.8 × 10^-5 m³

Question 64

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1 and that of steel is 12 × 10^-6 K^-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. If they are heated together to a higher temperature, at what temperature will the rod fit snugly in the pipe?

A) 305°C
B) 329°C
C) 341°C
D) 353°C
E) 376°C

Question 65

550 g of water at 105°C are poured into an 855 g aluminum container with an initial temperature of 11°C. The specific heat of aluminum is 900 J/(kg·K). How much heat flows from the water to the aluminum, assuming no heat is exchanged with the surroundings?

A) 55 kJ
B) 36 kJ
C) 54 kJ
D) 46 kJ
E) 64 kJ

Question 66

The Concorde's exterior is made of aluminum, which has a coefficient of linear expansion of 24 × 10^-6 K^-1. At 15°C, the Concorde measures 62.1 m in length. When the plane is in flight, friction with the air increases the temperature of the exterior skin to 200°C. What is the change in the length of the outer skin of the Concorde?

A) 20 cm
B) 24 cm
C) 28 cm
D) 32 cm
E) 36 cm

Question 67

The density of water at 0°C is 999.84 kg/m³ and at 4°C it is 999.96 kg/m³. A 1.0-liter container, full to the brim with water at 4°C is placed in the refrigerator. By the time that the temperature of the water reaches 0°C how much of the water has spilled from the container, assuming that the contraction of the container is negligible?

A) 1.1 × 10^-7 m³
B) 1.2 × 10^-7 m³
C) 1.3 × 10^-7 m³
D) 1.4 × 10^-7 m³
E) 1.5 × 10^-7 m³

Question 68

The coefficient of linear expansion of aluminum is 24 × 10^-6 K^-1 and the coefficient of volume expansion of olive oil is 0.68 × 10^-3 K^-1. A novice cook, in preparation for deep-frying some potatoes fills a 1.00-liter aluminum pot to the brim and heats the oil and the pot from an initial temperature of 15°C to 190°C. To his consternation some olive oil spills over the top. How much?

A) 0.11 liters
B) 0.12 liters
C) 0.13 liters
D) 0.14 liters
E) 0.15 liters

Question 69

The coefficient of linear expansion of aluminum is 24.0 × 10^-6 K^-1 and the density of aluminum at 0°C is 2.70 × 10³ kg/m³. What is the density of aluminum at 300°C?

A) 3.93 × 10³ kg/m³
B) 2.73 × 10³ kg/m³
C) 2.70 × 10³ kg/m³
D) 2.67 × 10³ kg/m³
E) 2.64 × 10³ kg/m³

Question 70

During a strenuous period of extravehicular activity, an astronaut generates 2.0 MJ of heat per hour, which must be removed by means of the liquid cooling and ventilating garment (LCVG) worn under the spacesuit. How much water must be circulated in the LCVG to remove this quantity of heat if it takes it from the astronaut at 37°C and dumps it at 0°C?

A) 1.5 kg/hr
B) 7.8 kg/hr
C) 13 kg/hr
D) 26 kg/hr
E) 480 kg/hr

Question 71

A person running in place on an exercise machine for 10 minutes uses up 17 Calories. Another person exercises by repeatedly lifting two 2.5-kg weights a distance of 50 cm. How many repetitions of this exercise are equivalent to 10 minutes of running?

A) 730
B) 1450
C) 1500
D) 2200
E) 2900

Question 72

A pendulum clock has a pendulum shaft made of aluminum which has a coefficient of linear expansion of 24.0 × 10^-6 K^-1. At 22°C the period of swing of the pendulum is 1.00 s. If the temperature is reduced to 5°C, how much time does the clock gain or lose in one day?

A) It gains 18 s per day.
B) It loses 18 s per day.
C) It gains 9.0 s per day.
D) It loses 9.0 s per day.
E) It neither gains nor loses time.

Question 73

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1 and that of steel is 12 × 10^-6 K^-1. At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm. To what temperature must the copper pipe be heated in order for the unheated rod to fit snugly in the pipe?

A) 53°C
B) 81°C
C) 93°C
D) 105°C
E) 143°C

Question 74

The coefficient of volume expansion of olive oil is 0.68 × 10^-3 K^-1. A 1-liter glass beaker is filled to the brim with olive oil at room temperature. The beaker is placed on a range and the temperature of the oil and beaker increases by 25°C As a result, 0.0167 liter of olive oil spill over the top of the beaker. What is the coefficient of linear expansion of glass?

A) 1 × 10^-6 K^-1
B) 4 × 10^-6 K^-1
C) 1 × 10^-5 K^-1
D) 2 × 10^-5 K^-1
E) 3 × 10^-5 K^-1

Question 75

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1. A sheet of copper has a round hole with a radius of 3.0 m cut out of it. If the sheet is heated and undergoes a change in temperature of 80 K, what is the change in the radius of the hole?

A) It decreases by 4.1 mm.
B) It increases by 4.1 mm.
C) It decreases by 8.2 mm.
D) It increases by 8.2 mm.
E) It does not change.

Question 76

At room temperature, a typical person loses energy to the surroundings at the rate of 62.0 W. If this energy loss has to be made up by an equivalent food intake, how many Calories does this person need to consume every day just to make up this heat loss?

A) 1040 Calories
B) 1160 Calories
C) 1280 Calories
D) 1340 Calories
E) 1400 Calories

Question 77

An aluminum electric tea kettle has a mass of 500 g. It has a 500-W heating coil. How long will it take to heat up 1.0 kg of water from 18°C to 98°C in the tea kettle? The specific heat of aluminum is 900 J/(kg·K).

A) 5 minutes
B) 7 minutes
C) 12 minutes
D) 15 minutes
E) 18 minutes

Question 78

How much heat is required to raise the temperature of a 225-g lead ball from 15.0°C to 25.0°C? The specific heat of lead is 128 J/(kg·K).

A) 725 J
B) 576 J
C) 145 J
D) 217 J
E) 288 J

Question 79

Suppose that an aluminum wire were to be strung out in a loop that just fits snugly around the equator (assuming a perfectly spherical Earth with a radius of 6.37 × 10⁶ m). If the temperature of the wire is increased by 0.50°C, and the increase in length is distributed equally through the entire length, how far off the ground will the wire loop be? The coefficient of linear expansion of aluminum is 24 × 10^-6 K^-1.

A) 7.6 mm
B) 76 mm
C) 76 cm
D) 76 m
E) 760 m

Question 80

A carpenter is driving a nail into a board. The 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. Assume that half of the kinetic energy of the hammer is transformed into heat in the 15.0-g steel nail and does not flow out. What is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? The specific heat of steel is 448 J/(kg·K).

A) 8.1 K
B) 3.6 K
C) 1.8 K
D) 2.7 K
E) 7.7 K