Chapter 10 - Temperature and Heat

A mixture consists of 50 g of ice and 60 g of liquid water, both at 0C. The amount of heat that must be added to melt all of the ice is about A. 4000 cal. B. 4800 cal. C. 21,600 cal. D. 32,400 cal.

A. 4000 cal.

A physics student has to make a choice in the color of shingles to put on her house. Considering only energy cost in heating and cooling the house, the decision of a light versus dark color roof will be based upon which of the following? A. A dark roof would be better in the winter but worse in summer. B. A light roof would be better in the winter but worse in summer. C. A light roof would be better in both the winter and summer. D. A dark roof would be better in both the winter and summer.

A. A dark roof would be better in the winter but worse in summer.

Two identical objects, one light colored and the other dark colored, are at the same elevated temperature, 50C. You now plop (yes, plop) them down in a dark, much cooler room. Which object will reach the room's temperature first? A. Dark colored B. Light colored C. Both reach room temperature at same time. D. As strange as it seems, neither object will ever reach room temperature because energy conservation prevents the loss of energy.

A. Dark colored

Two identical objects, one light colored and the other dark colored are at the same cool temperature. Then, you place them outside, on a warm day, in direct sunlight. Which object will warm up faster? A. The dark one. B. The light one. C. Both warm up at the same rate. D. As strange as it seems, neither object will ever warm up because energy conservation prevents the addition of energy.

A. The dark one.

When the temperature of the air in a balloon is raised, the volume of the balloon A. increases. B. stays the same. C. decreases. D. expands.

A. increases.

The specific heat capacity of ice is half that of water. If ice at -10 C is added to an equal amount of water at 10 C, then all the ice will melt and the final temperature of the water will be between 0 C and 10 C. This statement A. makes sense because the water contains more than enough heat to melt the ice. B. makes sense because water has more than enough temperature to melt the ice. C. does not make sense because it ignores the heat required to melt the ice. D. does not make sense because the final temperature will be 10 C.

A. makes sense because the water contains more than enough heat to melt the ice.

The temperature of a substance is A. proportional to the average kinetic energy of the molecules in a substance. B. equal to the kinetic energy of the fastest moving molecule in the substance. C. proportional to the lowest kinetic energy available to a molecule. D. proportional to the average momentum of the fastest 50% of the molecules in the substance.

A. proportional to the average kinetic energy of the molecules in a substance.

After I dip a cup of water from the ocean, I can conclude that A. the temperature of the water in the cup is the same as the temperature of the water in the ocean. B. the temperatures are the same but the water in the cup has more energy C. the ocean temperature is higher because it has more molecules in it. D. the ocean temperature is higher because it never loses its heat.

A. the temperature of the water in the cup is the same as the temperature of the water in the ocean.

Whenever a gas is compressed, A. work must be done on the gas. B. its internal energy must get smaller. C. heat must leave the gas. D. the temperature of the gas must get smaller.

A. work must be done on the gas.

Compare the internal energy of one gram of steam to that of one gram of water if both are at 100 C. A. The internal energy of the water and steam are the same. B. The internal energy of the water will be higher. C. The internal energy of the steam will be higher.

B. The internal energy of the water will be higher.

On a cold winter's morning you awake and step out of bed. One foot is on the tile floor and the other is on a rug on the floor. Which statement is true? A. The tile feels colder because it is smoother than the rug. B. The tile feels colder because it conducts heat more rapidly away from your foot. C. The tile feels colder because it is connected to the cold ground outside. D. The tile feels colder because it cannot absorb water like the rug can.

B. The tile feels colder because it conducts heat more rapidly away from your foot.

The space suits worn by astronauts prevent heat flows between the astronaut and their environment. In space, the kinds of heat flow that can occur are A. conduction and convection. B. conduction and radiation C. convection and radiation. D. All types of heat flow can occur.

B. conduction and radiation

Heat is a form of energy, and it has long been known that heat energy will naturally flow A. from cold to hot objects. B. from hot to cold objects. C. only from solids to liquids. D. only from liquids to solids. E. only from gases to solids and liquids.

B. from hot to cold objects.

After working hard outside on a hot summer day, placing a towel soaked in cold water on your head can feel very good. The reason the towel feels cold to you is that A. low temperature heat from conducts into your head, lowering your temperature. B. heat conducts from your head to the towel, lowering your temperature. C. cold air from the towel convects to your head. D. cold air radiates from the towel to your head.

B. heat conducts from your head to the towel, lowering your temperature.

Heat is added to an ideal gas and the gas expands. In such a process the temperature A. must always increase. B. will remain the same if the work done equals the heat added. C. must always decrease. D. will remain the same if work done is less than the heat added. E. will remain the same if the work done exceeds the heat added.

B. will remain the same if the work done equals the heat added.

The three processes by which heat energy is transferred between objects are A. heat, calorie and radiation. B. radiation, temperature, and convection. C. absorption, radiation, and convection. D. radiation, convection, and conduction. E. radiation, absorption, and conduction.

D. radiation, convection, and conduction.

When heat is added to a solid object, the ____________ of the object must increase.

Energy

The internal energy of a system such as helium gas can be identified as the total mechanical energy of the ______________.

Atoms

Four samples of steel, lead, alcohol and glass all have the same mass and are all initially at 20oC. After 100 calories of heat is added to each sample, the final temperatures are 38.2oC for the steel, 85.6oC for the lead, 23.4oC for the alcohol, and 30oC for the glass. Which of these four materials has the largest specific heat capacity? A. The steel. B. The lead. C. The alcohol. D. The glass. E. All have same heat capacity, since all absorbed 100 cal of heat.

C. The alcohol.

Absolute zero is the temperature A. on the coldest day recorded at Nome, Alaska. B. of the freezing point of water. C. at which an ideal gas would exert zero pressure. D. of the boiling point of liquid helium. E. of the freezing point of mercury.

C. at which an ideal gas would exert zero pressure.

Which of the following units is not an energy unit? A. Calorie. B. Joule. C. Kilowatt-hour. D. Horsepower. E. Kilocalorie.

D. Horsepower.

Water freezes at 273 on the ________ scale. A. Fahrenheit B. Celsius C. Rankin D. Kelvin E. Vernier

D. Kelvin

The amount of heat is often measured in calories. If I add 1 calorie of heat energy to 1 gram of water, the temperature of the water will A. decrease by 1C. B. decrease by 1F. C. stay the same since water has a very high specific heat. D. increase by 1C. E. increase by 1F.

D. increase by 1C.

Heat will not be transferred between two bodies that are at the same ____________________.

Temperature

A student uses a thermometer calibrated in Kelvin units. A temperature change of 10K is equivalent to a change of how many degrees on the Celsius scale?

10

Hot cider is poured into a metal cup. Shortly thereafter the handle of the cup becomes hot. This is due to the process of A. conduction. B. convection. C. radiation. D. osmosis.

A. conduction.

Which of the following temperatures is the lowest? A. 0oC B. 0oF C. 263 K D. All are the same.

B. 0oF

The temperature of 100 g of water is to be raised from 10 C to 60 C. The energy needed to do this is about A. 1 103 cal. B. 5 103 cal. C. 6 103 cal. D. 8 103 cal. E. 5.4 104 cal.

B. 5 103 cal.

While studying for this quiz you realize that you still have 100 g of lukewarm coffee at 40C left in a paper cup. When you pour 50 g of boiling water into the cup, the temperature of the resulting coffee-like mixture will be now A. 50 C. B. 60 C. C. 67 C. D. 70 C. E. 80 C.

B. 60 C.

Objects A and B are at the same temperature. Object A now has its temperature increased by one Fahrenheit degree, while B has its temperature increased by one Kelvin degree. Which object now has higher temperature? A. Object A. B. Object B. C. Both have the same temperature. D. Impossible to tell from this data.

B. Object B.

The lowest possible temperature a body can approach is called A. "mighty" cold. B. absolute zero. C. triple absolute zero. D. triple point. E. critical temperature.

B. absolute zero.

The term heat in physics is A. equivalent to temperature. B. equivalent to internal energy. C. any energy transferred to a body that raises the temperature of the body. D. energy transferred to a body because of a difference in temperature. E. the same as work.

D. energy transferred to a body because of a difference in temperature.

During the course of a demonstration the professor is called away. When he returns he finds a beaker of water that was at room temperature is now at a slightly higher temperature. There is a stirring rod on the desk and a cigarette lighter. The professor can assume that the temperature increase is due to A. heat added to the system. B. mechanical work done on the system. C. either heat added or mechanical work done.

C. either heat added or mechanical work done.

If you stand near a large fire, your face will be cooler if you place your hand between your face and the fire. Your hand is preventing heat flow by A. conduction. B. convection. C. radiation. D. latent heat.

C. radiation.

Heat flows into a gas in a piston and the gas performs some work on its surroundings. The amount of work done is less than the heat added. In this situation, A. the internal energy of the gas decreased. B. the internal energy of the gas did not change. C. the internal energy of the gas increased. D. the gas experienced a phase change. E. energy is not conserved and so it cannot happen.

C. the internal energy of the gas increased.

The transfer of heat from a furnace to the house through ducts is by the process of _________________.

Convection

When water boils, the primary form of heat flow in the water is ____________.

Convection

The temperature of a 50 g sample of aluminum is raised from 20oC to 90oC when 770 cal of heat is added. The specific heat capacity of the aluminum is A. not calculable from this data. B. 0.11 cal/g Co. C. 15.4 cal/g C. D. 0.22 cal/g C. E. 0.91 cal/g C.

D. 0.22 cal/g C.

A box of graham crackers is labeled "120 Calories per serving". Assuming this means 120 kcal, the energy of a serving of the graham crackers is about A. 120 J. B. 4.2 103 J. C. 5 104 J. D. 5 105 J.

D. 5 105 J.

An ice cube of mass 100 g and at 0oC is dropped into a Styrofoam cup containing 200 g of water at 25oC. The heat of fusion of ice is 80 cal/g and the specific heat capacity of water is 1.0 cal/g C. Assuming the cup does not exchange any heat with the outside, what will happen? A. All of the water will freeze. B. Some of the water will freeze. C. Nothing will happen. D. Some of the ice will melt. E. All of the ice will melt.

E. All of the ice will melt.

On a cold day, a metal fence post feels colder to the touch than a tree. This sensation of different temperatures is explained by the fact that A. the temperature of the tree is higher. B. the specific heat capacity of wood in the tree is higher. C. the specific heat capacity of the metal is higher. D. the thermal conductivity of the wood in the tree is higher. E. the thermal conductivity of the metal is higher.

E. the thermal conductivity of the metal is higher.

The first law of thermodynamics is an extension of the principle of conservation of _________________ that we first met in mechanics.

Energy

. During a phase change the ___________________ of a system will remain constant as heat is added.

Temperature