Question 1

If 25 kg of ice at 0°C is combined with 4 kg of steam at 100°C, what will be the final equilibrium temperature (in °C) of the system?

Accepted Answer

A)  40 
B)  20 
C)  60 
D)  100 
E)  8 
A)  40 
B)  20 
C)  60 
D)  100 
E)  8 B

Question 2

Determine the work done by 5 moles of an ideal gas that is kept at 100°C in an expansion from 1 liter to 5 liters.

Accepted Answer

A)  2.5 × 104 J 
B)  1.1 × 104 J 
C)  6.7 × 103 J 
D)  2.9 × 103 J 
E)  8.4 × 103 J 
A)  2.5 × 104 J 
B)  1.1 × 104 J 
C)  6.7 × 103 J 
D)  2.9 × 103 J 
E)  8.4 × 103 J A

Question 3

A gas expands as shown in the graph. If the heat taken in during this process is 1.02 × 106 J and 1 atm = 1.01 × 105 N/m2, the change in internal energy of the gas (in J) is

Accepted Answer

A)  −2.42 × 106 
B)  −1.40 × 106 
C)  −1.02 × 106 
D)  1.02 × 106 
E)  1.40 × 106 
A)  −2.42 × 106 
B)  −1.40 × 106 
C)  −1.02 × 106 
D)  1.02 × 106 
E)  1.40 × 106 B

Question 4

In an adiabatic free expansion

Accepted Answer

A)  no heat is transferred between a system and its surroundings. 
B)  the pressure remains constant. 
C)  the temperature remains constant. 
D)  the volume remains constant. 
E)  the process is reversible. 
A)  no heat is transferred between a system and its surroundings. 
B)  the pressure remains constant. 
C)  the temperature remains constant. 
D)  the volume remains constant. 
E)  the process is reversible.

Question 5

Five moles of an ideal gas expands isothermally at 100°C to five times its initial volume. Find the heat flow into the system.

Accepted Answer

A)  2.5 × 104 J 
B)  1.1 × 104 J 
C)  6.7 × 103 J 
D)  2.9 × 103 J 
E)  7.0 × 102 J 
A)  2.5 × 104 J 
B)  1.1 × 104 J 
C)  6.7 × 103 J 
D)  2.9 × 103 J 
E)  7.0 × 102 J

Question 6

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R1, R2 and R3, the overall R-value of the insulation is given by

Accepted Answer

A)  R = R1 + R2 + R3. 
B) 
  . 
C) 
  . 
D) 
  . 
E) 
  . 
A)  R = R1 + R2 + R3. 
B) 
  . 
C) 
  . 
D) 
  . 
E) 
  .

Question 7

For an astronaut working outside a spaceship, the greatest loss of heat would occur by means of

Accepted Answer

A)  conduction. 
B)  convection. 
C)  radiation. 
D)  conduction and convection. 
E)  conduction and radiation. 
A)  conduction. 
B)  convection. 
C)  radiation. 
D)  conduction and convection. 
E)  conduction and radiation.

Question 8

A 300-g glass thermometer initially at 25°C is put into 200 cm3 of hot water at 95°C. Find the final temperature (in °C) of the thermometer, assuming no heat flows to the surroundings. (The specific heat of glass is 0.2 cal/g⋅°C.)

Accepted Answer

A)  52 
B)  68 
C)  89 
D)  79 
E)  36 
A)  52 
B)  68 
C)  89 
D)  79 
E)  36

Question 9

Water at room temperature, 20°C, is pumped into a reactor core where it is converted to steam at 200°C. How much heat (in J) is transferred to each kilogram of water in this process? (csteam = 2 010 J/kg⋅°C; Lsteam = 2.26 × 103 J/g; 1 cal = 4.186 J.)

Accepted Answer

A)  3.35 × 105 
B)  7.53 × 105 
C)  2.67 × 106 
D)  2.80 × 106 
E)  3.01 × 106 
A)  3.35 × 105 
B)  7.53 × 105 
C)  2.67 × 106 
D)  2.80 × 106 
E)  3.01 × 106

Question 10

In an isothermal process

Accepted Answer

A)  the volume remains constant. 
B)  the temperature remains constant. 
C)  no heat is transferred between a system and its surroundings. 
D)  the pressure remains constant. 
E)  the internal energy is not constant. 
A)  the volume remains constant. 
B)  the temperature remains constant. 
C)  no heat is transferred between a system and its surroundings. 
D)  the pressure remains constant. 
E)  the internal energy is not constant.

Question 11

Gas in a container increases its pressure from 1 atm to 3 atm while keeping its volume constant. Find the work done (in J) by the gas if the volume is 5 liters.

Accepted Answer

A)  0 
B)  3 
C)  5 
D)  15 
E)  15 × 102 
A)  0 
B)  3 
C)  5 
D)  15 
E)  15 × 102

Question 12

A wall is constructed of a 2 inch layer of fiberglass board (R = 8) and six inches of fiberglass batting (R = 19). If the temperature on the outside surface of the fiberglass board is 50°F and the temperature on the inside surface of the fiberglass batting is 68°F, what is the temperature (in °F) at the interface? (The units of R are ft2⋅°F⋅h/BTU.)

Accepted Answer

A)  62 
B)  58 
C)  55 
D)  65 
E)  52 
A)  62 
B)  58 
C)  55 
D)  65 
E)  52

Question 13

Which of the following statements is correct?

Accepted Answer

A)  You only need to know the amount of thermal energy a body contains to calculate its temperature. 
B)  The temperature of a body is directly proportional to the amount of work the body has performed. 
C)  The quantity of thermal energy exchanged by two bodies in contact is inversely proportional to the difference in their temperatures. 
D)  The quantity of thermal energy exchanged by two bodies in contact is directly proportional to the difference in their temperatures. 
E)  Different amounts of thermal energy are transferred between two bodies in contact if different temperature scales are used to measure the temperature difference between the bodies. 
A)  You only need to know the amount of thermal energy a body contains to calculate its temperature. 
B)  The temperature of a body is directly proportional to the amount of work the body has performed. 
C)  The quantity of thermal energy exchanged by two bodies in contact is inversely proportional to the difference in their temperatures. 
D)  The quantity of thermal energy exchanged by two bodies in contact is directly proportional to the difference in their temperatures. 
E)  Different amounts of thermal energy are transferred between two bodies in contact if different temperature scales are used to measure the temperature difference between the bodies.

Question 14

How much water at 20°C is needed to melt 1 kilogram of solid mercury at its melting point of −39°C? (The heat of fusion of mercury is 2.8 cal/gram).

Accepted Answer

The answer of How much water at 20°C is needed...

Question 15

In an isobaric process

Accepted Answer

A)  the volume remains constant. 
B)  the temperature remains constant. 
C)  the pressure remains constant. 
D)  no heat is transferred between a system and its surroundings. 
E)  the internal energy is constant. 
A)  the volume remains constant. 
B)  the temperature remains constant. 
C)  the pressure remains constant. 
D)  no heat is transferred between a system and its surroundings. 
E)  the internal energy is constant.

Question 16

An 8 000-kg aluminum flagpole 100-m high is heated by the sun from a temperature of 10°C to 20°C. Find the increase in internal energy (in J) of the aluminum. (The coefficient of linear expansion is 24 × 10−6 (°C)−1, the density is 2.7 × 103 kg/m3, and the specific heat of aluminum is 0.215 cal/g⋅°C.)

Accepted Answer

A)  7.2 × 105 
B)  7.2 × 107 
C)  7.2 × 103 
D)  7.2 × 101 
E)  7.2 × 102 
A)  7.2 × 105 
B)  7.2 × 107 
C)  7.2 × 103 
D)  7.2 × 101 
E)  7.2 × 102

Question 17

In which process will the internal energy of the system NOT change?

Accepted Answer

A)  An adiabatic expansion of an ideal gas. 
B)  An isothermal compression of an ideal gas. 
C)  An isobaric expansion of an ideal gas. 
D)  The freezing of a quantity of liquid at its melting point. 
E)  The evaporation of a quantity of a liquid at its boiling point. 
A)  An adiabatic expansion of an ideal gas. 
B)  An isothermal compression of an ideal gas. 
C)  An isobaric expansion of an ideal gas. 
D)  The freezing of a quantity of liquid at its melting point. 
E)  The evaporation of a quantity of a liquid at its boiling point.

Question 18

A block of material of mass m and specific heat c falls from height h and reaches speed v just before striking the ground. Its temperature is measured immediately after it strikes the ground. If we ignore any change in temperature owing to interaction with the air, the change in temperature of the block of material is

Accepted Answer

A) 
  . 
B) 
  . 
C) 
  . 
D)  All of the answers above are correct. 
E)  Only (a) and (b) above are correct. 
A) 
  . 
B) 
  . 
C) 
  . 
D)  All of the answers above are correct. 
E)  Only (a) and (b) above are correct.

Question 19

Duff states that equal masses of all substances have equal changes in internal energy when they have equal changes in temperature. Javan states that the change in internal energy is equal to a constant times the change in temperature for every ΔT, no matter how large or how small ΔT is, but that the constant is different for different substances. Which one, if either, is correct?

Accepted Answer

A)  Neither, because the specific heat depends on the substance and may vary with temperature. 
B)  Neither, because a change of state may involve release or absorption of latent heat. 
C)  Neither because a substance may do work during a temperature change. 
D)  All of the statements above are correct. 
E)  Only statements (a) and (b) are correct. 
A)  Neither, because the specific heat depends on the substance and may vary with temperature. 
B)  Neither, because a change of state may involve release or absorption of latent heat. 
C)  Neither because a substance may do work during a temperature change. 
D)  All of the statements above are correct. 
E)  Only statements (a) and (b) are correct.

Question 20

How many calories of heat are required to raise the temperature of 4 kg of water from 50°F to the boiling point?

Accepted Answer

A)  6.5 × 105 
B)  3.6 × 105 
C)  15 × 105 
D)  360 
E)  4 × 104 
A)  6.5 × 105 
B)  3.6 × 105 
C)  15 × 105 
D)  360 
E)  4 × 104

Exam 20: The First Law of Thermodynamics

If 25 kg of ice at 0°C is combined with 4 kg of steam at 100°C, what will be the final equilibrium temperature (in °C) of the system?

Determine the work done by 5 moles of an ideal gas that is kept at 100°C in an expansion from 1 liter to 5 liters.

A gas expands as shown in the graph. If the heat taken in during this process is 1.02 × 106 J and 1 atm = 1.01 × 105 N/m2, the change in internal energy of the gas (in J) is

In an adiabatic free expansion

Five moles of an ideal gas expands isothermally at 100°C to five times its initial volume. Find the heat flow into the system.

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R1, R2 and R3, the overall R-value of the insulation is given by

For an astronaut working outside a spaceship, the greatest loss of heat would occur by means of

A 300-g glass thermometer initially at 25°C is put into 200 cm3 of hot water at 95°C. Find the final temperature (in °C) of the thermometer, assuming no heat flows to the surroundings. (The specific heat of glass is 0.2 cal/g⋅°C.)

Water at room temperature, 20°C, is pumped into a reactor core where it is converted to steam at 200°C. How much heat (in J) is transferred to each kilogram of water in this process? (csteam = 2 010 J/kg⋅°C; Lsteam = 2.26 × 103 J/g; 1 cal = 4.186 J.)

In an isothermal process

Gas in a container increases its pressure from 1 atm to 3 atm while keeping its volume constant. Find the work done (in J) by the gas if the volume is 5 liters.

Which of the following statements is correct?

How much water at 20°C is needed to melt 1 kilogram of solid mercury at its melting point of −39°C? (The heat of fusion of mercury is 2.8 cal/gram).

In an isobaric process

In which process will the internal energy of the system NOT change?

How many calories of heat are required to raise the temperature of 4 kg of water from 50°F to the boiling point?

Physics and Measurement

Motion in One Dimension

Vectors

Motion in Two Dimensions

The Laws of Motion

Circular Motion and Other Applications of Newtons Laws

Energy of a System

Conservation of Energy

Linear Momentum and Collisions

Rotation of a Rigid Object About a Fixed Axis

Angular Momentum

Static Equilibrium and Elasticity

Universal Gravitation

Fluid Mechanics

Oscillatory Motion

Wave Motion

Superposition and Standing Waves

Temperature

The Kinetic Theory of Gases

Heat Engines, Entropy, and the Second Law of Thermodynamics

Electric Fields

Gausss Law

Electric Potential

Capacitance and Dielectrics

Current and Resistance

Direct-Current Circuits

Magnetic Fields

Sources of the Magnetic Field

Faradays Law

Inductance

Alternating-Current Circuits

Electromagnetic Waves

The Nature of Light and the Principles of Ray Optics

Image Formation

Wave Optics

Diffraction Patterns and Polarization

Relativity

Introduction to Quantum Physics

Quantum Mechanics

Atomic Physics

Molecules and Solids

Nuclear Structure

Particle Physics and Cosmology

Filters

A gas expands as shown in the graph. If the heat taken in during this process is 1.02 × 10⁶ J and 1 atm = 1.01 × 10⁵ N/m², the change in internal energy of the gas (in J) is

The R-value of an insulating material is the thickness of the material divided by its thermal conductivity. When an insulating material consists of three layers with R-values R₁, R₂ and R₃, the overall R-value of the insulation is given by

A 300-g glass thermometer initially at 25°C is put into 200 cm³ of hot water at 95°C. Find the final temperature (in °C) of the thermometer, assuming no heat flows to the surroundings. (The specific heat of glass is 0.2 cal/g⋅°C.)

Water at room temperature, 20°C, is pumped into a reactor core where it is converted to steam at 200°C. How much heat (in J) is transferred to each kilogram of water in this process? (c_steam = 2 010 J/kg⋅°C; L_steam = 2.26 × 10³ J/g; 1 cal = 4.186 J.)