Deck 12: Thermal Properties of Matter

Question 1

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. During this process, if Object 1 absorbs heat Q, the amount of heat absorbed by Object 2 will be

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

Answer 1

E

Question 2

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper 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 one; both of them 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.

Answer 2

D

Question 3

The process in which heat flows by the mass movement of molecules from one place to another is known as

A) conduction.
B) convection.
C) radiation.

Answer 3

B

Question 4

Which one of the following quantities is the smallest unit of heat energy?

A) calorie
B) kilocalorie
C) Btu
D) joule

Question 5

If the absolute temperature of an object is tripled, the thermal power radiated by this object (assuming that its emissivity and size are not affected by the temperature change) will

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 6

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper 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 one; both of them 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 7

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 the figure. The rods can be placed in parallel, as shown on the left, or in series, as on the right. When steady state flow is established, 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.

Question 8

On a cold day, a piece of metal feels much colder to the touch than a piece of wood. This is due to the difference in which one of the following physical properties of these materials?

A) density
B) specific heat
C) emissivity
D) thermal conductivity
E) mass

Question 9

An object having a fixed emissivity of 0.725 radiates heat at a rate of 10 W when it is at an absolute temperature T. If its temperature is doubled to 2T, at what rate will it now radiate?

A) 20 W
B) 40 W
C) 80 W
D) 160 W
E) 320 W

Question 10

If, with steady state heat flow established, you double the thickness of a wall built from solid uniform material, the rate of heat loss for a given temperature difference across the thickness will

A) become one-half its original value.
B) also double.
C) become one-fourth its original value.
D) become 1/ of its original value.
E) become four times its original value.

Question 11

As shown in the figure, 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.

Question 12

The figure shows a graph of the temperature of a pure substance as a function of time as heat is added to it at a constant rate in a closed container. If L_F is the latent heat of fusion of this substance and L_V is its latent heat of vaporization, what is the value of the ratio L_V/L_F?

A) 5.0
B) 4.5
C) 7.2
D) 3.5
E) 1.5

Question 13

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 denser and the hollow one less dense.
E) the solid sphere becomes less dense and the hollow one denser.

Question 14

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 15

If you wanted to know how much the temperature of a particular piece of material would rise when a known amount of heat was added to it, which of the following quantities would be most helpful to know?

A) initial temperature
B) specific heat
C) density
D) coefficient of linear expansion
E) thermal conductivity

Question 16

A solid cylindrical bar conducts heat at a rate of 25 W from a hot to a cold reservoir under steady state conditions. If both the length and the diameter of this bar are doubled, the rate at which it will conduct heat between these reservoirs will be

A) 200 W
B) 100 W
C) 50 W
D) 25 W
E) 12.5 W

Question 17

By what primary heat transfer mechanism does the sun warm the earth?

A) convection
B) conduction
C) radiation
D) All of the above processes are equally important in combination.

Question 18

Consider a flat steel plate with a hole through its center as shown in the figure. When the temperature of the plate 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 as the plate expands into it.
D) always expand with the plate.
E) remain the same size as the plate expands around it.

Question 19

The coefficient of linear expansion for aluminum is 1.8 × 10^-6 K^-1. What is its coefficient of volume expansion?

A) 9.0 × 10^-6 K^-1
B) 5.8 × 10^-18 K^-1
C) 5.4 × 10^-6 K^-1
D) 3.6 × 10^-6 K^-1
E) 0.60 × 10^-6 K^-1

Question 20

An architect is interested in estimating the rate of heat loss, ΔQ/Δt, through a sheet of insulating material as a function of the thickness of the sheet. Assuming fixed temperatures on the two faces of the sheet and steady state heat flow, which one of the graphs shown in the figure best represents the rate of heat transfer as a function of the thickness of the insulating sheet?

A) A
B) B
C) C
D) D
E) E

Question 21

An ideal gas is held in a container of volume V at pressure p. The rms speed of a gas molecule under these conditions is v. If now the volume and pressure are changed to 2V and 2p, the rms speed of a molecule will be

A) v/2
B) v
C) 2v
D) 4v
E) v/4

Question 22

An ideal gas is compressed isothermally to one-third of its initial volume. The resulting pressure will be

A) three times as large as the initial value.
B) less than three times as large as the initial value.
C) more than three times as large as the initial value.
D) equal to the initial value.
E) impossible to predict on the basis of this data.

Question 23

Two containers of equal volume each hold samples of the same ideal gas. Container A has twice as many molecules as container B. If the gas pressure is the same in the two containers, the correct statement regarding the absolute temperatures T_A and T_B in containers A and B, respectively, is

A) T_A = T_B.
B) T_A = 2T_B.
C) T_A = T_B.
D) T_A = T_B.
E) T_A = T_B.

Question 24

A mole of diatomic oxygen molecules and a mole of diatomic nitrogen molecules are at STP. Which statements are true about these molecules? (There could be more than one correct choice.)

A) Both gases have the same average molecular speeds.
B) Both gases have the same number of molecules.
C) Both gases have the same average kinetic energy per molecule.
D) Both gases have the same average momentum per molecule.

Question 25

The absolute temperature of an ideal gas is directly proportional to which of the following quantities?

A) the average speed of its molecules
B) the average momentum of its molecules
C) the average kinetic energy of its molecules
D) the mass of its molecules
E) It is proportional to all of the above quantities.

Question 26

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, how do their average molecular speeds compare? The oxygen molecules are moving

A) four times faster than the hydrogen molecules.
B) at 1/4 the speed of the hydrogen molecules.
C) sixteen times faster than the hydrogen molecules.
D) at 1/16 the speed of the hydrogen molecules.
E) at 1/ the speed of the hydrogen molecules.

Question 27

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct?

A) The gas must absorb heat from its surroundings.
B) The gas must release heat to its surroundings.
C) The pressure of the gas also stays constant.
D) The process is adiabatic.
E) It is impossible to predict on the basis of this data.

Question 28

A sample of an ideal gas is heated and its Kelvin temperature doubles. If the root-mean-square speed of its molecules was originally v, what is the new root-mean-square speed?

A) 4v
B) 2v
C) v
D) v/
E) v/4

Question 29

When a gas expands adiabatically,

A) the internal (thermal) energy of the gas decreases.
B) the internal (thermal) energy of the gas increases.
C) it does no work.
D) work is done on the gas.
E) the temperature of the gas remains constant.

Question 30

A fixed container holds oxygen and helium gases at the same temperature. Which of the following statements are correct? (There could be more than one correct choice.)

A) The oxygen molecules have the greater average kinetic energy.
B) The helium molecules have the greater average kinetic energy.
C) The oxygen molecules have the greater speed.
D) The helium molecules have the greater speed.
E) The helium molecules have the same average kinetic as the oxygen molecules.

Question 31

A certain ideal gas has a molar specific heat at constant volume 7R/2. What is its molar specific heat at constant pressure?

A) 5R/2
B) 3R/2
C) 8R
D) 9R/2
E) 6R

Question 32

For an ideal gas,

A) C_P = C_V for all ideal gases.
B) C_P > C_V for all ideal gases.
C) C_P < C_V for all ideal gases.
D) it depends on whether the gas is monatomic or diatomic.

Question 33

The root-mean-square speed of the molecules of an ideal gas is v. The gas is now slowly compressed to one-half its original volume with no change in temperature. What is the root-mean-square speed of the molecules now?

A) 4v
B) 2v
C) v/
D) v
E) v/2

Question 34

The absolute temperature of a gas is T. In order to double the rms speed of its molecules, what should be the new absolute temperature?

A) 4T
B) 2T
C) T
D) 8T
E) 16T

Question 35

A certain ideal gas has a molar specific heat at constant pressure of 7R/2. What is its molar specific heat at constant volume?

A) 5R/2
B) 3R/2
C) 8R
D) 9R/2
E) 6R

Question 36

An ideal gas is compressed isobarically to one-third of its initial volume. The resulting pressure will be

A) three times as large as the initial value.
B) equal to the initial value.
C) more than three times as large as the initial value.
D) impossible to predict on the basis of this data.

Question 37

A certain ideal gas has a molar specific heat at constant pressure of 33.2 J/mol ∙ K. Its molar specific heat at constant volume is closest to which of the following values? (R = 8.31J/mol ∙ K)

A) 41.9 J/mol ∙ K
B) 16.6 J/mol ∙ K
C) 25.1 J/mol ∙ K
D) 24.9 J/mol ∙ K
E) 49.8 J/mol ∙ K

Question 38

For an ideal gas,

A) = 1 for all ideal gases.
B) < 1 for all monatomic and diatomic gases.
C) > 1 for all monatomic and diatomic gases.
D) < 1 only for a monatomic gas.
E) < 1 only for a diatomic gas.

Question 39

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules,

A) is greater.
B) is less.
C) is the same.
D) cannot be determined without knowing the pressure and volume.

Question 40

Consider two equal-volume flasks of gas at the same temperature and pressure. One gas, oxygen, has a molecular mass of 32. The other gas, nitrogen, has a molecular mass of 28. What is the ratio of the number of oxygen molecules to the number of nitrogen molecules in these flasks?

A)
B)
C)
D)
E)

Question 41

Suppose that a rigid 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 over the entire length, how far off the ground will the wire loop be if it remained centered on the earth? 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 42

A hole in a brass plate has a diameter of 1.200 cm at 20°C. What is the diameter of the hole when the plate is heated to 220°C? The coefficient of linear thermal expansion for brass is 19 × 10^-6 K^-1.

A) 1.205 cm
B) 1.195 cm
C) 1.200 cm
D) 1.210 cm

Question 43

For the mercury in a thermometer to expand from 4.00 cm³ to 4.10 cm³, what change in temperature is necessary? The mercury has a volume expansion coefficient of 1.80 × 10^-4 K^-1.

A) 400 C°
B) 140 C°
C) 14 C°
D) 8.2 C°

Question 44

A gas is taken through the cycle shown in the pV diagram in the figure. During one cycle, how much work is done by the gas?

A) p₀V₀
B) 2 p₀V₀
C) 3 p₀V₀
D) 4 p₀V₀

Question 45

A mercury thermometer has a glass bulb of interior volume 0.100 cm³ at 10°C. The glass capillary tube above the bulb has an inner cross-sectional area of 0.012 mm². The coefficient of volume expansion of mercury is 1.8 × 10^-4 K^-1. If the expansion of the glass is negligible, how much will the mercury rise in the capillary tube when the temperature rises from 5°C to 35°C if the bulb was full at 5°C?

A) 0.45 mm
B) 4.5 mm
C) 45 mm
D) 45 cm

Question 46

An aluminum rod 17.400 cm long at 20°C is heated to 100°C. What is its new length? Aluminum has a linear expansion coefficient of 25 × 10^-6 K^-1.

A) 17.435 cm
B) 17.365 cm
C) 0.348 cm
D) 0.0348 cm

Question 47

A steel bridge is 1000 m long at -20°C in winter. What is the change in length when the temperature rises to 40°C in summer? The average coefficient of linear expansion of this steel is 11 × 10^-6 K^-1.

A) 0.33 m
B) 0.44 m
C) 0.55 m
D) 0.66 m

Question 48

Two processes are shown on the pV diagram in the figure. One of them is an adiabat and the other one is an isotherm. Which process is the isotherm?

A) process A
B) process B
C) The processes shown are neither isotherms nor adiabats.
D) It is not possible to tell without knowing if the gas is monatomic or diatomic.

Question 49

The volume coefficient of thermal expansion for gasoline is 950 × 10^-6 K^-1. By how many cubic centimeters does the volume of 1.00 L of gasoline change when the temperature rises from 30°C to 50°C?

A) 6.0 cm³
B) 12 cm³
C) 19 cm³
D) 37 cm³

Question 50

By what length will a slab of concrete that is originally 18 m long contract when the temperature drops from 24°C to -16°C? The coefficient of linear thermal expansion for this concrete is 1.0 × 10^-5 K^-1.

A) 0.50 cm
B) 0.72 cm
C) 1.2 cm
D) 1.5 cm

Question 51

A quantity of mercury occupies 400.0 cm³ at 0°C. What volume will it occupy when heated to 50°C? Mercury has a volume expansion coefficient of 180 × 10^-6 K^-1.

A) 450 cm³
B) 409.7 cm³
C) 403.6 cm³
D) 401.8 cm³

Question 52

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 from winter to summer?

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

Question 53

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) 14 × 10^-5 m³

Question 54

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 of some pesto, fills a 1.00-L 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 L
B) 0.12 L
C) 0.13 L
D) 0.14 L
E) 0.15 L

Question 55

A large vat contains 1.000 L of water at 20°C. What volume will this water occupy when it is heated up to 80°C? Water has a volume expansion coefficient of 210 × 10^-6 K^-1.

A) 1.600 L
B) 1.013 L
C) 0.987 L
D) 0.9987 L

Question 56

The process shown on the TV graph in the figure is an

A) adiabatic compression.
B) isothermal compression.
C) isochoric compression.
D) isobaric compression.

Question 57

The process shown on the pV diagram in the figure is

A) adiabatic.
B) isothermal.
C) isochoric.
D) isobaric.

Question 58

The process shown on the pV diagram in the figure is an

A) adiabatic expansion.
B) isothermal expansion.
C) isometric expansion.
D) isobaric expansion.

Question 59

The coefficient of volume expansion of a certain olive oil is 0.68 × 10^-3 K^-1. A 1.0-L 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 L of olive oil spills over the top of the beaker. Which of the following values is closest to the coefficient of linear expansion of the glass from which the beaker is made?

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 60

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 61

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. Which one of the following quantities is closest to the temperature to which the copper pipe must be heated in order for the unheated steel rod to fit snugly in the copper pipe?

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

Question 62

A brass rod is 69.5 cm long and an aluminum rod is 49.3 cm long when both rods are at an initial temperature of 0° C. The rods are placed in line with a gap of 1.2 cm between them, as shown in the figure. The distance between the far ends of the rods is maintained at 120.0 cm throughout. The temperature of both rods is raised equally until they are barely in contact. At what temperature does contact occur? The coefficients of linear expansion of brass and aluminum are 2.0 ×10^-5 K^-1 (brass) and 2.4 × 10^-5 K^-1 (aluminum).

A) 470°C
B) 440°C
C) 420°C
D) 490°C
E) 510°C

Question 63

A 920-g empty iron kettle is put on a stove. How much heat in joules must it absorb to raise its temperature form to The specific heat for iron is 113 cal/kg ∙ C°, and 1 cal = 4.186 J.

A) 33,900 J
B) 40,500 J
C) 8110 J
D) 40,100 J

Question 64

A steel pipe 36.0 m long, installed when the temperature was is used to transport superheated steam at a temperature of Steel's coefficient of linear expansion is . The pipe is allowed to expand freely when the steam is transported. What is the increase in the length of the pipe when it is used with the superheated steam?

A) 60 mm
B) 57 mm
C) 54 mm
D) 64 mm
E) 67 mm

Question 65

A 6.5-g iron meteor hits the earth at a speed of 295 m/s. If its kinetic energy is entirely converted to heat in the meteor, by how much will its temperature rise? The specific heat of iron is 113 cal/kg ∙ C°, and 1 cal = 4.186 J.

A) 92.0 C°
B) 57,100 C°
C) 0.147 C°
D) 384 C°

Question 66

A glass flask has a volume of 500 mL at a temperature of 20° C. The flask contains 492 mL of mercury at an equilibrium temperature of 20°C. The temperature is raised until the mercury reaches the 500 mL reference mark. At what temperature does this occur? The coefficients of volume expansion of mercury and glass are 18 ×10^-5 K^-1 (mercury) and 2.0 ×10^-5 K^-1 (glass).

A) 120°C
B) 110°C
C) 100°C
D) 140°C
E) 130°C

Question 67

An aluminum electric tea kettle with a mass of 500 g is heated with 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 and that of water is 4186 J/kg ∙ K.

A) 5.0 minutes
B) 7.0 minutes
C) 12 minutes
D) 15 minutes
E) 18 minutes

Question 68

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 69

A solid object has a volume density ρ₀ at a temperature of 315 K. The coefficient of volume expansion for the material of which it is made is 7.00 × 10^-5 K^-1. What will be its density (in terms of ρ₀ at a temperature of 425 K, assuming that it does not melt and that its thermal properties do not change with temperature?

Question 70

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 71

A 5.00-g lead BB moving at 44.0 m/s penetrates a wood block and comes to rest inside the block. If half of its kinetic energy is absorbed by the BB, what is the change in the temperature of the BB? The specific heat of lead is 128 J/kg ∙ K.

A) 0.940 K
B) 1.10 K
C) 1.26 K
D) 2.78 K
E) 3.78 K

Question 72

A container of 114.0 g of water is heated using of power, with perfect efficiency. How long will it take to raise the temperature of the water from to The specific heat capacity of the container is negligible, and the specific heat capacity of water is 4.186 × 10³ J/kg ∙ C.

A) 71 s
B) 4.1 s
C) 17 s
D) 320,000 s

Question 73

A 4.0-kg aluminum block is originally at 10°C. If 160 kJ of heat is added to the block, what is its final temperature? The specific heat capacity of aluminum is 910 J/kg ∙ K.

A) 24°C
B) 34°C
C) 44°C
D) 54°C

Question 74

A carpenter is driving a 15.0-g steel nail into a board. His 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. Half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. 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

Question 75

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, which one of the following quantities is closest to the common temperature at which the steel rod will fit snugly in the copper pipe?

A) 310°C
B) 330°C
C) 340°C
D) 350°C
E) 380°C

Question 76

An aluminum rod is 10.0 cm long and a steel rod is 80.0 cm long when both rods are at a temperature of 15°C. Both rods have the same diameter. The rods are now joined end-to-end to form a rod 90.0 cm long. If the temperature is now raised from 15°C to 90°C, what is the increase in the length of the joined rod? The coefficient of linear expansion of aluminum is 2.4 × 10^-5 K^-1 and that of steel is 1.2 × 10^-5 K^-1.

A) 0.90 mm
B) 0.81 mm
C) 0.72 mm
D) 0.63 mm
E) 0.99 mm

Question 77

If 150 kcal of heat raises the temperature of 2.0 kg of a material by 400 F°, what is the specific heat capacity of the material?

A) 1.35 kcal/kg ∙ C°
B) 0.75 kcal/kg ∙ C°
C) 0.34 kcal/kg ∙ C°
D) 0.19 kcal/kg ∙ C°

Question 78

A machine part consists of 0.10 kg of iron (of specific heat 470 J/kg ∙ K ) and 0.16 kg of copper (of specific heat 390 J/kg ∙ K). How much heat must be added to the gear to raise its temperature from 18°C to 53°C?

A) 910 J
B) 3800 J
C) 4000 J
D) 4400 J

Question 79

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-L container, full to the brim with water at 4.0°C is placed in the refrigerator. By the time that the temperature of the water reaches 0.0°C, what volume of 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 80

It is necessary to determine the specific heat of an unknown object. The mass of the object is It is determined experimentally that it takes to raise the temperature What is the specific heat of the object?

A) 7.46 J/kg ∙ K
B) 1500 J/kg ∙ K
C) 0.00130 J/kg ∙ K
D) 3,020,000 J/kg ∙ K