?Rank, from greatest to least, the magnitudes of these units of thermal energy: (a) 1

Temperature What are the temperatures for freezing water on the Celsius and the Fahrenheit scales, respectively? For boiling water?

Temperature Is the temperature of an object a measure of the total translational kinetic energy of molecules in the object or a measure of the average translational kinetic energy per molecule in the object?

Temperature Under what condition does a thermometer measure the temperature of its surroundings? (Why do we say that “a thermometer measures its own temperature”?)

Absolute Zero By how much does the pressure of a gas in a rigid vessel decrease when the temperature is decreased from \(0^{\circ} \mathrm{C}\) to \(-1^{\circ} \mathrm{C}\)? Text Transcription: 0^circ C -1^circ C

Absolute Zero What pressure would you expect in a rigid container of \(0^{\circ} \mathrm{C}\) gas cooled to \(-273^{\circ} \mathrm{C}\)? Text Transcription: 0^circ C -273^circ C

Absolute Zero What are the temperatures for freezing water and boiling water on the Kelvin temperature scale?

Absolute Zero How much energy can be removed from a system at 0 K?

Heat In which direction does thermal energy flow between hot and cold objects?

Heat Does a hot object contain thermal energy, or does it contain heat?

Heat How does heat differ from thermal energy?

Heat What role does temperature have in the direction of thermal energy flow?

Quantity of Heat Why is heat measured in joules?

Quantity of Heat How many joules are needed to change the temperature of 1 gram of water by \(1^{\circ} \mathrm{C}\)? Text Transcription: 1^circ C

Quantity of Heat Cite a way in which the energy value of foods is determined.

Quantity of Heat Distinguish among a calorie, a Calorie, and a joule.

The Laws of Thermodynamics Which law of thermodynamics consists of the conservation of energy applied to thermal systems?

The Laws of Thermodynamics What becomes of heat that is added to a system but doesn’t increase the temperature of the system?

The Laws of Thermodynamics Which law of thermodynamics is related to the direction of heat transfer?

The Laws of Thermodynamics When can thermal energy in a system move from lower to higher temperatures?

The Laws of Thermodynamics Which law of thermodynamics is related to a system reaching 0 K?

Entropy When disorder in a system increases, does entropy increase or decrease?

Entropy Under what condition can the entropy of a system be decreased?

Specific Heat Capacity Which warms faster when heat is applied: iron or silver? Which has the lower specific heat capacity?

Specific Heat Capacity How does the specific heat capacity of water compare with the specific heat capacities of other common materials?

Specific Heat Capacity What is the relationship between water’s high specific heat capacity and Europe’s climate?

Thermal Expansion Why does a bimetallic strip bend with changes in temperature?

Thermal Expansion Which generally expands more for an equal increase in temperature: solids or liquids?

Expansion of Water When the temperature of ice-cold water is increased slightly, does it undergo a net expansion or a net contraction?

Expansion of Water What is the reason for ice being less dense than water?

Expansion of Water At what temperature do the combined effects of contraction and expansion produce the smallest volume of water?

How much energy is in a nut? Burn it and find out. The heat from the flame is energy released when carbon and hydrogen in the nut combine with oxygen in the air (oxidation reactions) to produce \(\mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\). Pierce a nut (pecan or walnut halves work best) with a bent paper clip that holds the nut above the table surface. Above this, secure a can of water so that you can measure its temperature change when the nut burns. Use about \(10^{3} \mathrm{~cm}\) (10 mL) of water and a Celsius thermometer. As soon as you ignite the nut with a match, place the can of water above it, and record the increase in water temperature once the flame burns out. The number of calories released by the burning nut can be calculated by the formula \(Q=c m \Delta T\) , where c is the water’s specific heat \(\left(1 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)\), m is the mass of water, and \(\Delta T\) is the change in temperature. The energy in food is expressed in terms of the Calorie, which is 1000 of the calories you’ll measure. So to find the number of Calories, divide your result by 1000. (See Think and Solve Exercise 36.) Text Transcription: CO_2 H_2 O 10^3 cm Q=cm Delta T (1 cal/g cdot ^circ C) Delta T

Write a letter to your grandparents describing how you’re learning to see connections in nature that have eluded you until now, and how you’re learning to distinguish between related ideas. Use temperature and heat as examples.

Use the formula above to show that it takes 3000 cal to raise the temperature of 300 g of water from \(20^{\circ} \mathrm{C}\) to \(30^{\circ} \mathrm{C}\). For the specific heat capacity c, use \(\left(1 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)\). Text Transcription: 20^circ C 30^circ C (1 cal/g cdot ^circ C)

Use the same formula to show that it takes 12,570 joules to raise the temperature of the same mass (0.30 kg) of water through the same temperature interval. For the specific heat capacity c, use \(4,190 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\) . Text Transcription: 4,190 J/kg cdot ^circ C

Show that 3000 cal = 12,570 J, the same quantity of thermal energy in different units.

Will Maynez burns a 0.6-g peanut beneath 50 g of water, which increases in temperature from \(22^{\circ} \mathrm{C}\) to \(50^{\circ} \mathrm{C}\). (The specific heat capacity of water is \(1.0 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\).) (a) Assuming 40% efficiency, show that the peanut’s food value is 3500 calories. (b) Then show how the food value in calories per gram is 5.8 kcal/g (or 5.8 Cal/g). Text Transcription: 22^circ C 50^circ C 1.0 cal/g cdot ^circ C

Consider a 6.0-g steel nail 8.0 cm long and a hammer that exerts an average force of 600 N on the nail when it is being driven into a piece of wood. The nail becomes warmer. Show that the increase in the nail’s temperature is \(17.8^{\circ} \mathrm{C}\). (Assume that the specific heat capacity of steel is \(450 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\).) Text Transcription: 17.8^circ C 450 J/kg cdot ^circ C

If you wish to warm 50 kg of water by \(20^{\circ} \mathrm{C}\) for your bath, show that the amount of heat needed is 1000 kcal (1000 Cal). Then show that this rounds off to be about 4200 kJ. Text Transcription: 20^circ C

The specific heat capacity of steel is \(450 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\). Show that the amount of heat needed to raise the temperature of a 10-kg piece of steel from \(0^{\circ} \mathrm{C}\) to \(100^{\circ} \mathrm{C}\) is 450,000 J. How does this compare with the heat needed to raise the temperature of the same mass of water through the same temperature difference? (For water, \(c=4190 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\).) Text Transcription: 450 J/kg cdot ^circ C 0^circ C 100^circ C c = 4190 J/kg cdot ^circ C

In the lab, you submerge 100 g of \(40^{\circ} \mathrm{C}\) nails in 200 g of \(20^{\circ} \mathrm{C}\) water. (The specific heat of iron is \(0.12 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\).) Equate the heat gained by the water to the heat lost by the nails, and show that the final temperature of the water is about \(21^{\circ} \mathrm{C}\). Text Transcription: 40^circ C 20^circ C 0.12 cal/g cdot ^circ C 21^circ C

Consider a 1-m bar that expands 0.6 cm when heated. Show that when similarly heated, a 100-m bar of the same material becomes 100.6 m long.

Suppose that the 1.3-km main span of steel for the Golden Gate Bridge had no expansion joints. Show that for an increase in temperature of \(20^{\circ} \mathrm{C}\), the bridge would be nearly 0.3 m longer. Text Transcription: 20^circ C

Imagine people breathing on the length of a 40,000-km steel pipe that forms a ring to fit snugly entirely around the circumference of Earth so as to raise its temperature by \(1^{\circ} \mathrm{C}\). The pipe gets longer—and is no longer snug. How high does it then stand above ground level? Show that the answer is an astounding 70 m higher! (To simplify, consider only the expansion of its radial distance from the center of Earth, and apply the geometry formula that relates circumference C and radius r—that is, \(C=2 \pi r\)) Text Transcription: 1^circ C C=2pi r

Rank, from greatest to least, the magnitudes of these units of thermal energy: (a) 1 calorie. (b) 1 Calorie. (c) 1 joule.

Three blocks of metal at the same temperature are placed on a hot stove. Their specific heat capacities are given, after their identities, in the list that follows. Rank these blocks of metal, from greatest to least, in terms of how quickly they warm up: (a) Steel, \(450 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\). (b) Aluminum, \(910 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\). (c) Copper, \(390 \mathrm{~J} / \mathrm{kg} \cdot{ }^{\circ} \mathrm{C}\). Text Transcription: 450 J/kg cdot ^circ C 910 J/kg cdot ^circ C 390 J/kg cdot ^circ C

How much the lengths of various substances change with temperature changes is given by their coefficients of linear expansion, \(\alpha\). The greater the value of \(\alpha\), the greater the change in length for a given change in temperature. Three kinds of metal wires are stretched between distant telephone poles. Rank these wires, from greatest to least, in terms of how much they will sag on a hot summer day: (a) Copper, \(\alpha=17 \times 10^{-6} /{ }^{\circ} \mathrm{C}\). (b) Aluminum, \(\alpha=24 \times 10^{-6} /{ }^{\circ} \mathrm{C}\). (c) Steel, \(\alpha=11 \times 10^{-6} /{ }^{\circ} \mathrm{C}\). Text Transcription: alpha alpha=17 times 10^-6 / ^circ C alpha=24 times 10^-6 / ^circ C alpha=11 times 10^-6 / ^circ C

The precise volume of 200 grams of water in a beaker depends on the temperature of the water. Rank the following temperatures from greatest volume of 200 grams of water to least volume of 200 grams of water: (a) \(0^{\circ} \mathrm{C}\). (b) \(4^{\circ} \mathrm{C}\). (c) \(10^{\circ} \mathrm{C}\). Text Transcription: 0^circ C 4^circ C 10^circ C

Temperature A friend says that molecules in a mixture of gases in thermal equilibrium have the same average kinetic energy. Do you agree or disagree? Defend your answer.

Temperature A friend says that molecules in a mixture of gases in thermal equilibrium have the same average speed. Do you agree or disagree? Defend your answer.

Temperature A friend tells you that the surface temperature of a particular star is 50,000 degrees. You’re not sure whether your friend meant Celsius degrees or kelvins. How much difference is involved in this ambiguity?

Temperature Why would you expect the molecules in a gas to have a variety of speeds?

Temperature Consider two glasses, one filled with water and the other half full, both at the same temperature. In which glass are the water molecules moving faster? In which is there greater thermal energy? In which will more heat be required to increase the temperature by \(1^{\circ} \mathrm{C}\)? Text Transcription: 1^circ C

Temperature Which is greater: an increase in temperature of \(1^{\circ} \mathrm{C}\) or an increase of \(1^{\circ} \mathrm{F}\)? Text Transcription: 1^circ C 1^circ F

Temperature Which contains the greater amount of thermal energy: an iceberg or a cup of hot coffee? Defend your answer.

Absolute Zero On which temperature scale does the average kinetic energy of molecules double when the temperature doubles?

Absolute Zero What will be the temperature of a \(0^{\circ} \mathrm{C}\) steel block if its thermal energy is doubled? Text Transcription: 0^circ C

Absolute Zero What will be the temperature of \(0^{\circ} \mathrm{C}\) helium gas if its thermal energy is halved? Text Transcription: 0^circ C

Heat What name is given to “thermal energy in transit”?

Heat Instead of saying a red-hot horseshoe contains heat, it is correct to say a red-hot horseshoe contains what?

Heat What is the general direction of the flow of thermal energy? What is the name of that flow?

Quantity of Heat Which of these involves the most thermal energy: 1 calorie, 1 Calorie, or 1 joule?

Quantity of Heat Which of these involves the least thermal energy: 1 calorie, 1 Calorie, or 1 joule?

Quantity of Heat Which raises the temperature of water more: the addition of 1 calorie or of 1 joule?

The Laws of Thermodynamics If 100 joules of heat is added to a system that does no external work, by how much is the thermal energy of the system raised?

The Laws of Thermodynamics If 100 joules of heat is added to a system that does 40 joules of external work, by how much is the thermal energy of the system raised?

The Laws of Thermodynamics Which law of thermodynamics tells us what is most probable in nature?

The Laws of Thermodynamics Which law of thermodynamics involves absolute zero?

The Laws of Thermodynamics Under what conditions can thermal energy in a system move from cold to hot?

Entropy Entropy is a measure of how energy becomes disorderly in a system. Disorder increases and entropy increases. How is this related to opening a bottle of perfume in the corner of a room?

Entropy In the previous question, there is a reason why all the gas molecules in our room don’t suddenly rush to one corner, leaving us in a vacuum gasping for breath. Does the fact that air naturally spreads out mean that entropy increases or that it decreases?

Entropy What happens to the gas pressure within a sealed gallon can when it is heated? When it is cooled? Defend your answers.

Entropy After a car is driven along a road for some distance, why does the air pressure in the tires increase?

Specific Heat Capacity Why does adding the same amount of heat to two different objects of the same mass not necessarily produce the same increase in temperature?

Specific Heat Capacity What does the high specific heat of water have to do with the convection currents in the air at the seashore?

Specific Heat Capacity Why does jello stay cooler for a longer time than sandwiches when both are removed from a picnic cooler on a hot day?

Specific Heat Capacity When a 1-kg metal pan containing 1 kg of cold water is removed from the refrigerator and set on a table, which absorbs more heat from the room—the pan or the water?

Specific Heat Capacity Which undergoes a greater change in temperature when heat is applied: 1 kg of water or 1 kg of iron? Defend your answer.

Specific Heat Capacity Which has the greater specific heat capacity: an object that cools quickly or an object of the same mass that cools more slowly?

Specific Heat Capacity Desert sand is very hot in the day and very cool at night. What does this tell you about its specific heat?

Specific Heat Capacity On cold winter nights in days past, it was common to take a heated object to bed with you. Which would keep you warmer through the cold night: a 10-kg iron brick or a 10-kg jug of hot water at the same high temperature? Explain.

Specific Heat Capacity Why does the presence of large bodies of water tend to moderate the climate of nearby land, making it warmer in cold weather and cooler in hot weather?

Specific Heat Capacity If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow only cherry trees and Washington, D.C. only palm trees?

Specific Heat Capacity Compared with conventional water heaters in the United States, why do propane tankless water heaters (which are common in other parts of the world) cost up to 60% less to operate?

Thermal Expansion Would a bimetallic strip of two different metals function if each metal had the same rate of expansion? Is it important that the metals expand at different rates? Defend your answer.

Thermal Expansion In terms of thermal expansion, why is it important that a lock and its key be made of the same material or of similar materials?

Thermal Expansion Why are incandescent bulbs typically made of very thin glass?

Thermal Expansion For many years, a method for breaking boulders was putting them in a hot fire and then dousing them with cold water. Why would the boulders fracture?

Thermal Expansion An old technique for separating a pair of nested wedged-together drinking glasses is to run water at different temperatures into the inner glass and over the surface of the outer glass. Which water should be hot and which cold?

Thermal Expansion A metal ball is barely able to pass through a metal ring. When Anette Zetterberg heats the ball, it does not pass through the ring. What happens if she instead heats the ring (as shown)? Does the size of the hole increase, stay the same, or decrease?

Thermal Expansion Suppose you cut a small gap in a metal ring. If you heat the ring, does the gap become wider or narrower?

Expansion of Water State an exception to the claim that all substances expand when heated.

Expansion of Water How does the combined volume of the billions of hexagonal open spaces in the structures of ice crystals in a piece of ice compare with the portion of ice that floats above the water line?

Expansion of Water A piece of solid iron sinks in a container of molten iron. A piece of solid aluminum sinks in a container of molten aluminum. Why does a piece of solid water (ice) not sink in a container of “molten” (liquid) water? Explain, using molecular terms.

In your room are things such as tables, chairs, and other people. Which of these things has a temperature (1) lower than that of the air, (2) greater than that of the air, and (3) equal to the temperature of the air?

Why can’t you determine whether you are running a fever by touching your own forehead?

The temperature of the Sun’s interior is about \(10^{7}\) . Does it matter whether this is degrees Celsius or kelvins? Defend your answer. Text Transcription: 10^7

If you drop a hot rock into a pail of water, the temperature of the rock and that of the water change until both are equal. The rock cools and the water warms. Does this hold true if the hot rock is dropped into the Atlantic Ocean? Defend your answer.

Structural groaning and creaking noises are sometimes heard in the attic of old buildings on cold nights. Give an explanation in terms of thermal expansion.

portant that glass mirrors that have a low “coefficient of expansion” be used in astronomical observatories?

Steel plates are commonly attached to each other with rivets. A rivet is a small metal cylinder, rounded on one end and blunt on the other end. After a hot rivet is inserted in a hole joining the two plates, its blunt end is rounded with a hammer, which is made easier by the hotness of the rivet. How does the hotness of the rivet also help to make a tight fit when it cools?

After a machinist quickly slips a hot, snugly fitting iron ring over a very cold brass cylinder, the two metals cannot be separated intact. Can you explain why this is so?

Suppose that water is used in a thermometer instead of mercury. If the temperature is \(4^{\circ} \mathrm{C}\) and then changes, why doesn’t the thermometer indicate whether the temperature is rising or falling? Text Transcription: 4^circ C

If cooling occurred at the bottom of a pond instead of at the surface, would a lake freeze from the bottom up? Explain.