Question 1

Of the following systems,which contains the most heat?

Accepted Answer

A)  100 kg of water at 80°C 
B)  250 kg of water at 40°C 
C)  600 kg of ice at 0°C 
D)  Systems do not contain heat. 
A)  100 kg of water at 80°C 
B)  250 kg of water at 40°C 
C)  600 kg of ice at 0°C 
D)  Systems do not contain heat.

Question 2

A person has a thermal conductivity of 0.18 W/m·K between his inner core and his skin with an effective shell thickness of 1.6 cm between his core and skin.If his inner core is at the normal 98.6°F,and his skin has a surface area of 1.62 m2,what will be his rate of loss of thermal energy due to conduction through his skin if his skin temperature is 31.0°C?
​

Accepted Answer

A)  68 W 
B)  123 W 
C)  177 W 
D)  109 W 
E)  ​175 W 
A)  68 W 
B)  123 W 
C)  177 W 
D)  109 W 
E)  ​175 W

Question 3

An object at 29°C has its temperature increased to 41°C.The power then radiated by this object increases by how many percent?
​

Accepted Answer

A)  30 
B)  17 
C)  4 
D)  41 
E)  ​96 
A)  30 
B)  17 
C)  4 
D)  41 
E)  ​96

Question 4

Which of the following involves the greatest heat transfer?

Accepted Answer

A)  One gram of steam at 100°C changing to water at 100°C. 
B)  One gram of ice at 0°C changing to water at 0°C. 
C)  One gram of water cooling from 100°C to 0°C. 
D)  One gram of ice heating from −100°C to 0°C. 
A)  One gram of steam at 100°C changing to water at 100°C. 
B)  One gram of ice at 0°C changing to water at 0°C. 
C)  One gram of water cooling from 100°C to 0°C. 
D)  One gram of ice heating from −100°C to 0°C.

Question 5

Twenty grams of a solid at 70°C is place in 100 grams of a fluid at 20°C.Thermal equilibrium is reached at 30°C.The specific heat of the solid:

Accepted Answer

A)  is equal to that of the fluid. 
B)  is less than that of the fluid. 
C)  is more than that of the fluid. 
D)  cannot be compared to that of a material in a different phase. 
A)  is equal to that of the fluid. 
B)  is less than that of the fluid. 
C)  is more than that of the fluid. 
D)  cannot be compared to that of a material in a different phase.

Question 6

If cooking is done using an aluminum pan over an electric burner,which of the following will not promote the rate of heat flow from burner to food?

Accepted Answer

A)  increase pan bottom thickness 
B)  increase pan bottom area 
C)  increase burner temperature 
D)  decrease height of pan sides 
A)  increase pan bottom thickness 
B)  increase pan bottom area 
C)  increase burner temperature 
D)  decrease height of pan sides

Question 7

How many calories are equal to four BTU? (One calorie = 4.186 J,one BTU = 1 054 J. )

Accepted Answer

A)  1.007 
B)  15.89 
C)  1007 
D)  1589 
A)  1.007 
B)  15.89 
C)  1007 
D)  1589

Question 8

A plot of the temperature versus the energy per kg added to a piece of ice as it goes from below freezing at − 10°C to becoming steam at 110°C consists of straight lines,some horizontal and some with an upward slope.What do the upward slopes represent?

Accepted Answer

A)  specific heats 
B)  reciprocals of specific heats 
C)  latent heats 
D)  reciprocals of latent heats 
A)  specific heats 
B)  reciprocals of specific heats 
C)  latent heats 
D)  reciprocals of latent heats

Question 9

Two stars,A and B,have the same emissivity,but the radii and surface temperatures are different with RA = 0.5 RB,and TA = 2 TB.Assuming the temperature of space to be negligible,which star radiates the most energy per unit time?

Accepted Answer

A)  Star A 
B)  Star B 
C)  Both radiate the same amount of energy per unit time. 
D)  More information is needed in order to make a determination. 
A)  Star A 
B)  Star B 
C)  Both radiate the same amount of energy per unit time. 
D)  More information is needed in order to make a determination.

Question 10

A waterfall is 150 m high.What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s2,cw = 4,186 J/kg⋅°C)

Accepted Answer

A)  0.18°C 
B)  0.35°C 
C)  1.05°C 
D)  0.44°C​ 
E)  0.70°C 
A)  0.18°C 
B)  0.35°C 
C)  1.05°C 
D)  0.44°C​ 
E)  0.70°C

Question 11

A windowpane is half a centimeter thick and has an area of 0.9 m2.The temperature difference between the inside and outside surfaces of the pane is 14 °C.What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s⋅m⋅°C. )
​

Accepted Answer

A)  4,200 J/s 
B)  2,100 J/s 
C)  2,500 J/s 
D)  1,510 J/s 
E)  ​1,800 J/s 
A)  4,200 J/s 
B)  2,100 J/s 
C)  2,500 J/s 
D)  1,510 J/s 
E)  ​1,800 J/s

Question 12

Carly places one end of a steel bar in a Bunsen flame and the other end in an ice cube.By what factor is the rate of heat flow changed when the bar's cross-sectional area is doubled?

Accepted Answer

A)  2 
B)  1/2 
C)  4.0 
D)  1/4 
A)  2 
B)  1/2 
C)  4.0 
D)  1/4

Question 13

If a 1,000-kg car was moving at 35 m/s,what would be its kinetic energy expressed in the unusual (for kinetic energy)units of calories? (1 cal = 4.186 J)

Accepted Answer

A)  0.4 × 104 
B)  6.1 × 105 
C)  1.2 × 106 
D)  1.5 × 105 
E)  0.8 × 104 
A)  0.4 × 104 
B)  6.1 × 105 
C)  1.2 × 106 
D)  1.5 × 105 
E)  0.8 × 104

Question 14

Consider two different rods.The greatest thermal conductivity will be in the rod with:

Accepted Answer

A)  electrons that are freer to move from atom to atom. 
B)  the greater specific heat. 
C)  the greater cross-sectional area. 
D)  the greater length. 
A)  electrons that are freer to move from atom to atom. 
B)  the greater specific heat. 
C)  the greater cross-sectional area. 
D)  the greater length.

Question 15

Iced tea is made by adding ice to 1.7 kg of hot tea,initially at 85°C.How many kg of ice,initially at 0°C,are required to bring the mixture to 10°C? (Lf = 3.33 × 105 J/kg,cw = 4 186 J/kg⋅°C)

Accepted Answer

A)  1.8 kg 
B)  1.2 kg 
C)  1.4 kg 
D)  1.0 kg 
E)  1.6 kg 
A)  1.8 kg 
B)  1.2 kg 
C)  1.4 kg 
D)  1.0 kg 
E)  1.6 kg

Question 16

Arrange from smallest to largest: the BTU,the joule,and the calorie.

Accepted Answer

A)  BTU,J,cal 
B)  J,cal,BTU 
C)  cal,BTU,J 
D)  J,BTU,cal 
A)  BTU,J,cal 
B)  J,cal,BTU 
C)  cal,BTU,J 
D)  J,BTU,cal

Question 17

140 g of liquid nitrogen at its boiling point of 77 K is stirred into a beaker containing 510 g of 16°C water.If the nitrogen leaves the solution as soon as it turns to gas,how much water freezes? The heat of vaporization of nitrogen is 48 cal/g and that of water is 80 cal/g.

Accepted Answer

A)  none 
B)  23 g 
C)  46 g 
D)  12 g 
E)  ​92 g 
A)  none 
B)  23 g 
C)  46 g 
D)  12 g 
E)  ​92 g

Question 18

A 0.1-kg aluminum plate,initially at 20°C,slides down a 14-m-long surface,inclined at a 29° angle to the horizontal.The force of kinetic friction exactly balances the component of gravity down the plane so that the plate,once started,glides down at constant velocity.If 90% of the mechanical energy of the system is absorbed by the aluminum,what is its temperature increase at the bottom of the incline? (Specific heat for aluminum is 900 J/kg⋅°C. )
​

Accepted Answer

A)  0.120 C° 
B)  0.07 C° 
C)  0.67 C° 
D)  1.03 C° 
E)  59.86 C° 
A)  0.120 C° 
B)  0.07 C° 
C)  0.67 C° 
D)  1.03 C° 
E)  59.86 C°

Question 19

The first experiment,which systematically demonstrated the equivalence of mechanical energy and heat,was performed by:

Accepted Answer

A)  Joule. 
B)  Boltzmann. 
C)  Thompson,Count Rumford. 
D)  Kelvin. 
A)  Joule. 
B)  Boltzmann. 
C)  Thompson,Count Rumford. 
D)  Kelvin.

Question 20

Sea breezes that occur near the shore are attributed to a difference between land and water with respect to what property?

Accepted Answer

A)  mass density 
B)  coefficient of volume expansion 
C)  specific heat 
D)  emissivity 
A)  mass density 
B)  coefficient of volume expansion 
C)  specific heat 
D)  emissivity

Exam 11: Energy in Thermal Processes Heat and Internal Energy

Of the following systems,which contains the most heat?

An object at 29°C has its temperature increased to 41°C.The power then radiated by this object increases by how many percent? ​

Which of the following involves the greatest heat transfer?

Twenty grams of a solid at 70°C is place in 100 grams of a fluid at 20°C.Thermal equilibrium is reached at 30°C.The specific heat of the solid:

If cooking is done using an aluminum pan over an electric burner,which of the following will not promote the rate of heat flow from burner to food?

How many calories are equal to four BTU? (One calorie = 4.186 J,one BTU = 1 054 J. )

A plot of the temperature versus the energy per kg added to a piece of ice as it goes from below freezing at − 10°C to becoming steam at 110°C consists of straight lines,some horizontal and some with an upward slope.What do the upward slopes represent?

Two stars,A and B,have the same emissivity,but the radii and surface temperatures are different with RA = 0.5 RB,and TA = 2 TB.Assuming the temperature of space to be negligible,which star radiates the most energy per unit time?

A waterfall is 150 m high.What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s2,cw = 4,186 J/kg⋅°C)

A windowpane is half a centimeter thick and has an area of 0.9 m2.The temperature difference between the inside and outside surfaces of the pane is 14 °C.What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s⋅m⋅°C. ) ​

Carly places one end of a steel bar in a Bunsen flame and the other end in an ice cube.By what factor is the rate of heat flow changed when the bar's cross-sectional area is doubled?

If a 1,000-kg car was moving at 35 m/s,what would be its kinetic energy expressed in the unusual (for kinetic energy)units of calories? (1 cal = 4.186 J)

Consider two different rods.The greatest thermal conductivity will be in the rod with:

Iced tea is made by adding ice to 1.7 kg of hot tea,initially at 85°C.How many kg of ice,initially at 0°C,are required to bring the mixture to 10°C? (Lf = 3.33 × 105 J/kg,cw = 4 186 J/kg⋅°C)

Arrange from smallest to largest: the BTU,the joule,and the calorie.

140 g of liquid nitrogen at its boiling point of 77 K is stirred into a beaker containing 510 g of 16°C water.If the nitrogen leaves the solution as soon as it turns to gas,how much water freezes? The heat of vaporization of nitrogen is 48 cal/g and that of water is 80 cal/g.

The first experiment,which systematically demonstrated the equivalence of mechanical energy and heat,was performed by:

Sea breezes that occur near the shore are attributed to a difference between land and water with respect to what property?

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

Filters

An object at 29°C has its temperature increased to 41°C.The power then radiated by this object increases by how many percent?

Two stars,A and B,have the same emissivity,but the radii and surface temperatures are different with R_A = 0.5 R_B,and T_A = 2 T_B.Assuming the temperature of space to be negligible,which star radiates the most energy per unit time?

A waterfall is 150 m high.What is the increase in water temperature at the bottom of the falls if all the initial potential energy goes into heating the water? (g = 9.8 m/s²,c_w = 4,186 J/kg⋅°C)

A windowpane is half a centimeter thick and has an area of 0.9 m².The temperature difference between the inside and outside surfaces of the pane is 14 °C.What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s⋅m⋅°C. )

Iced tea is made by adding ice to 1.7 kg of hot tea,initially at 85°C.How many kg of ice,initially at 0°C,are required to bring the mixture to 10°C? (L_f = 3.33 × 10⁵ J/kg,c_w = 4 186 J/kg⋅°C)