Physics Chapter 21 & 24 ExamName:

Date:

______1.Temperature is related mostly to the _____.

  1. average molecular kinetic energy in a substance
  2. total kinetic energy in something
  3. average energy in a substance
  4. total energy in something
  5. average kinetic energy of an object

______2.Which temperature scale labels the freezing point of water at 0 degrees?

  1. a.Celsius
  2. b.Caloric
  3. c.Kelvin
  4. d.Fahrenheit
  5. e.none of the above

______3.3.Heat is the _____.

  1. a.average amount of energy per molecule contained in an object
  2. b.total amount of energy contained in an object
  3. c.energy transferred between objects because of a temperature difference
  4. d.amount of energy all the molecules have
  5. e.all of the above

______4.Internal energy is the _____.

  1. a.average amount of energy contained in an object
  2. b.amount of energy that is transferred from one object to another object
  3. c.total amount of energy contained in an object
  4. d.amount of kinetic energy all the molecules have
  5. e.all of the above

______5.Heat is measured in _____.

  1. a.kilocalories
  2. b.joules
  3. c.calories
  4. d.all of the above
  5. e.none of the above

______6.The energy content of a piece of food is normally determined by _____.

  1. a.eating the piece of food
  2. b.measuring the volume of the food
  3. c.burning the food
  4. d.none of the above

______7.Some molecules are able to absorb large amounts of energy in the form of internal vibrations and rotations. Materials composed of such molecules would have _____.

  1. a.high specific heat capacities
  2. b.low specific heat capacities

______8.Specific heat capacity is related to the amount of internal energy _____.

  1. a.transferred by one molecule
  2. b.one molecule contains
  3. c.a specific object has
  4. d.transferred by one object
  5. e.needed to change the temperature of one kilogram of a substance one degree

______9.Which has the higher specific heat capacity, water or sand?

  1. a.Water
  2. b.Sand
  3. c.They both have the same specific heat capacity.

______10.The reason an ocean's temperature doesn't vary much from one season to the next is that _____.

  1. a.oceans are located in mild regions of the Earth
  2. b.oceans are located next to large land areas
  3. c.water has a high specific heat capacity
  4. d.water has a low specific heat capacity
  5. e.there are a lot of fish in the oceans

______11.The largest extremes in temperature are usually experienced _____.

  1. a.on islands
  2. b.near the oceans
  3. c.in the middle of a continent
  4. d.in Japan
  5. e.near large coastal cities like San Francisco

______12.The fact that desert sand is very hot in the day and very cold at night is evidence that sand has a _____.

  1. a.low specific heat capacity
  2. b.high specific heat capacity

______13.If the specific heat capacity of water were higher than it is, lakes would be _____.

  1. a.more likely to freeze
  2. b.less likely to freeze
  3. c.neither of the above

______14.During a very cold winter, water pipes sometimes burst. The reason for this is _____.

  1. a.water expands when freezing
  2. b.water contracts when freezing
  3. c.the ground contracts when colder, pulling pipes apart
  4. d.the thawing process releases pressure on the pipes
  5. e.none of the above

______15.8000 Joules of heat are added to 1 kilogram of water when its temperature is 40°C. The resulting temperature of the water is

  1. a.46°C
  2. b.39°C
  3. c.42°C
  4. d.50°C

______16.A change in temperature of 10°C is equal to a change of

  1. a.–273 K
  2. b.10 K
  3. c.263 K
  4. d.273 K
  5. e.283 K

______17.Mix a liter of 60°C water with 2 liters of 40°C water and you'll have 3 liters of water at _____.

  1. a.50°C
  2. b.53°C
  3. c.25°C
  4. d.47°C

______18.Which is denser, ice at 0 degrees C or water at 4 degrees C?

  1. a.The water
  2. b.The ice
  3. c.They both have the same density.

______19.The lowest possible temperature is

  1. a.–273 degrees C.
  2. b.4 K.
  3. c.0 degrees C.

______20.The first law of thermodynamics is a restatement of the

  1. Carnot cycle.
  2. law of heat addition.
  3. principle of entropy.
  4. conservation of energy.
  5. none of the above

______21.The greater the difference in temperature between the input reservoir and output reservoir for a heat engine, the

  1. less the efficiency.
  2. greater the efficiency.
  3. neither—efficiency doesn't depend on temperature difference.

______22.When mechanical work is done on a system, there can be an increase in its

  1. temperature.
  2. internal energy.
  3. both of the above
  4. none of the above

______23.When work is done by a system and no heat is added to it, the temperature of the system

  1. remains unchanged.
  2. decreases.
  3. increases.

______24.When a volume of air is compressed and no heat enters or leaves, the air temperature will

  1. increase.
  2. remain unchanged.
  3. decrease.

______25.Suppose the temperature of the input reservoir in a heat engine doesn't change. As the sink temperature is lowered, the efficiency of the engine

  1. stays the same.
  2. decreases.
  3. increases.

______26.Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This would violate the

  1. first law of thermodynamics.
  2. second law of thermodynamics.
  3. both of the above
  4. none of the above

______27.As a system becomes more disordered, entropy

  1. remains the same.
  2. decreases.
  3. increases.

______28.Systems that are left alone tend to move toward a state of

  1. more entropy.
  2. less entropy.
  3. no entropy.

______29.Entropy measures

  1. temperature as volume increases.
  2. temperature as pressure increases.
  3. temperature at constant pressure.
  4. messiness.
  5. temperature at constant volume.

______30.Entropy is closely related to the

  1. second law of thermodynamics.
  2. first law of thermodynamics.
  3. both of the above
  4. none of the above

______31.Running a refrigerator with its door open in a hot room makes the room

  1. cooler.
  2. warmer.
  3. none of the above.

______32.Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses

  1. volume.
  2. pressure.
  3. both A and B
  4. neither A nor B

______33.Ceramic automobile engines that can operate at higher temperatures will be

  1. less efficient.
  2. more efficient.
  3. neither of the above.

______34.The ideal efficiency for a heat engine operating between temperatures of 2050 K and 310 K is

  1. 15%.
  2. 50%.
  3. 25%.
  4. 85%.
  5. none of the above.

______35.80 joules of heat is added to a system that performs 55 Joules of work. The internal energy change of the system is

  1. 0 J.
  2. 25 J.
  3. 55 J.
  4. 135 J.
  5. none of the above.

Indicate whether the sentence or statement is true or false.

______36.The average kinetic energy of molecules in a substance is related to temperature.

______37.A temperature scale that has 100 degrees between the boiling point and the freezing point of water is the Fahrenheit scale.

______38.Heat is the energy that moves from one object to another because of a temperature difference.

______39.The total of all energies in a substance is its temperature.

______40.A Joule is a common unit of force.

______41.The amount of heat required to change the temperature of a unit mass of a substance by 1 degree is its specific heat capacity.

______42.Liquids usually expand when heated.

______43.Gases don't expand very much when heated.

______44.It is possible to wholly convert a given amount of heat energy into mechanical energy.

______45.It is possible to totally convert a given amount of mechanical energy into heat.

______46.Systems left alone tend to move to a state of greater entropy.

______47.Efficiency in a heat engine is increased when there is a greater difference in input and output temperatures.

______48.If all the friction could be eliminated in a heat engine, its efficiency would be 100%.

______49.Whenever heat is added to a system, it transforms to an equal amount of some other form of energy.

Solve & Explain

______50.Give two reasons why a tire pump becomes hotter when used to pump a tire.

______51.What amount of heat is required to raise the temperature of 150 grams of water by 20°C?

______52.An absolute temperature of 473 K is the same as what Celsius temperature?

______53.Give both the Kelvin and Celsius temperatures for absolute zero, freezing point and boiling point.

______54.The temperature of an object is raised by 70ºC. This is equivalent to what increase in its absolute temperature?

______55.Calculate the ideal efficiency of a power plant that runs between temperatures 400 K and 150 K.

______56.If 5000J of heat is added to a heat engine but only 3500J of work is done by the engine, what happens to the remaining energy?