Name:     Period: 
 
Email  (No email = No Credit): 
 

Note:  These "Exam" results are submitted to Mr. Morrison at admin@mobiophys.com
The exact SAME QUESTIONS Along with DETAILED EXPLANATIONS can be found here Online Exam Index Link
by choosing the corresponding  "STUDY GUIDE VERSION"

STUDY GUIDE VERSION

 Solutions to the written questions are to be found in the unit answers link.


Heat&Thermodynamics

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

Temperature is related mostly to the _____.
a.
average molecular kinetic energy in a substance
b.
total kinetic energy in something
c.
average energy in a substance
d.
total energy in something
e.
average kinetic energy of an object
 

 2. 

Which temperature scale labels the freezing point of water at 0 degrees?
a.
Celsius
b.
Caloric
c.
Kelvin
d.
Fahrenheit
e.
none of the above
 

 3. 

Heat is the _____.
a.
average amount of energy per molecule contained in an object
b.
total amount of energy contained in an object
c.
energy transferred between objects because of a temperature difference
d.
amount of energy all the molecules have
e.
all of the above
 

 4. 

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

 5. 

Heat is measured in _____.
a.
kilocalories
b.
joules
c.
calories
d.
all of the above
e.
none of the above
 

 6. 

The energy content of a piece of food is normally determined by _____.
a.
eating the piece of food
b.
measuring the volume of the food
c.
burning the food
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 _____.
a.
high specific heat capacities
b.
low specific heat capacities
 

 8. 

Specific heat capacity is related to the amount of internal energy _____.
a.
transferred by one molecule
b.
one molecule contains
c.
a specific object has
d.
transferred by one object
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?
a.
Water
b.
Sand
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 _____.
a.
oceans are located in mild regions of the Earth
b.
oceans are located next to large land areas
c.
water has a high specific heat capacity
d.
water has a low specific heat capacity
e.
there are a lot of fish in the oceans
 

 11. 

The largest extremes in temperature are usually experienced _____.
a.
on islands
b.
near the oceans
c.
in the middle of a continent
d.
in Japan
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 _____.
a.
low specific heat capacity
b.
high specific heat capacity
 

 13. 

Which, starting at the same temperature, will warm more slowly on a hot day?
a.
Dry beans
b.
Watermelon
c.
Potatoes
d.
Bread
e.
All will cool at the same or similar rates.
 

 14. 

If the specific heat capacity of water were higher than it is, lakes would be _____.
a.
more likely to freeze
b.
less likely to freeze
c.
neither of the above
 

 15. 

During a very cold winter, water pipes sometimes burst. The reason for this is _____.
a.
water expands when freezing
b.
water contracts when freezing
c.
the ground contracts when colder, pulling pipes apart
d.
the thawing process releases pressure on the pipes
e.
none of the above
 

 16. 

The reason fish live from year to year in ponds that freeze over in the winter is that _____.
a.
fish are cold-blooded and can stand being frozen and thawed
b.
fish swim so fast they keep the water from freezing under the surface
c.
water below the ice is 4 degrees above freezing
d.
fish hibernate during the winter
e.
none of the above
 

 17. 

One thousand calories of heat are added to 150 grams of water when its temperature is 33°C. The resulting temperature of the water is
a.
7°C
b.
32°C
c.
40°C
d.
80°C
e.
100°C
 

 18. 

A change in temperature of 10°C is equal to a change of
a.
–273 K
b.
10 K
c.
263 K
d.
273 K
e.
283 K
 

 19. 

Mix some 70°C water with some 40°C water and you'll get water at _____.
a.
a temperature depending on the masses (or volumes) of water
b.
40°C
c.
55°C
d.
70°C
 

 20. 

Mix a liter of 60°C water with 2 liters of 40°C water and you'll have 3 liters of water at _____.
a.
50°C
b.
53°C
c.
25°C
d.
47°C
 

 21. 

Mix 3 liters of 20°C water with 4 liters of 30°C water and you'll have 7 liters of water at _____.
a.
28°C
b.
32°C
c.
26°C
d.
24°C
 

 22. 

Which releases the most energy, 100 grams of 100°C water cooling to 50°C, or 100 grams of iron at 100°C cooling to 50°C? (The specific heat of iron is 450 J/Kg°C.)
a.
Iron
b.
Water
c.
both the same
 

 23. 

Which is denser, ice at 0 degrees C or water at 4 degrees C?
a.
The water
b.
The ice
c.
They both have the same density.
 

 24. 

The lowest possible temperature is
a.
–273 degrees C.
b.
4 K.
c.
0 degrees C.
 

 25. 

The first law of thermodynamics is a restatement of the
a.
Carnot cycle.
b.
law of heat addition.
c.
principle of entropy.
d.
conservation of energy.
e.
none of the above
 

 26. 

The greater the difference in temperature between the input reservoir and output reservoir for a heat engine, the
a.
less the efficiency.
b.
greater the efficiency.
c.
neither—efficiency doesn't depend on temperature difference.
 

 27. 

When mechanical work is done on a system, there can be an increase in its
a.
temperature.
b.
internal energy.
c.
both of the above
d.
none of the above
 

 28. 

When work is done by a system and no heat is added to it, the temperature of the system
a.
remains unchanged.
b.
decreases.
c.
increases.
 

 29. 

When a volume of air is compressed and no heat enters or leaves, the air temperature will
a.
increase.
b.
remain unchanged.
c.
decrease.
 

 30. 

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
a.
stays the same.
b.
decreases.
c.
increases.
 

 31. 

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
a.
first law of thermodynamics.
b.
second law of thermodynamics.
c.
both of the above
d.
none of the above
 

 32. 

As a system becomes more disordered, entropy
a.
remains the same.
b.
decreases.
c.
increases.
 

 33. 

Systems that are left alone tend to move toward a state of
a.
more entropy.
b.
less entropy.
c.
no entropy.
 

 34. 

Entropy measures
a.
temperature as volume increases.
b.
temperature as pressure increases.
c.
temperature at constant pressure.
d.
messiness.
e.
temperature at constant volume.
 

 35. 

Entropy is closely related to the
a.
second law of thermodynamics.
b.
first law of thermodynamics.
c.
both of the above
d.
none of the above
 

 36. 

Running a refrigerator with its door open in a hot room makes the room
a.
cooler.
b.
warmer.
c.
none of the above.
 

 37. 

In buildings that are electrically heated, turning the lights on
a.
doesn't waste energy.
b.
wastes energy.
c.
does neither of the above.
 

 38. 

Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses
a.
volume.
b.
pressure.
c.
both A and B
d.
neither A nor B
 

 39. 

Ceramic automobile engines that can operate at higher temperatures will be
a.
less efficient.
b.
more efficient.
c.
neither of the above.
 

 40. 

The ideal efficiency for a heat engine operating between temperatures of 2050 K and 310 K is
a.
15%.
b.
50%.
c.
25%.
d.
85%.
e.
none of the above.
 

 41. 

80 joules of heat is added to a system that performs 55 Joules of work. The internal energy change of the system is
a.
0 J.
b.
25 J.
c.
55 J.
d.
135 J.
e.
none of the above.
 

True/False
Indicate whether the sentence or statement is true or false.
 

 42. 

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

 43. 

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

 44. 

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

 45. 

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

 46. 

A Joule is a common unit of force.
 

 47. 

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

 48. 

Liquids usually expand when heated.
 

 49. 

Gases don't expand very much when heated.
 

 50. 

A bimetallic strip consists of two strips of the same material welded together.
 

 51. 

Water contracts when heated from 0 degrees C to 4 degrees C.
 

 52. 

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

 53. 

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

 54. 

Air high in the atmosphere that plunges downward tends to cool.
 

 55. 

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

 56. 

When work is done by a system on something else, the temperature of the system decreases.
 

 57. 

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

 58. 

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

 59. 

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

Essay:  These are the updated and final version of the practice written questions for the exam.

Click here to go to answers to questions below, after trying to do them first of course!  Written Questions

 

 60. 

Explain why putting a dented table-tennis ball in a pot of boiling water will help remove the dent.
 

 61. 

Use the example of a barn to illustrate that natural systems tend to proceed toward greater entropy.  Explain Entropy in your answer!
 

 62. 

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

 63. 

Use gasoline in your car as an example to explain that energy becomes less organized when it transforms from one form to another.
 

 64. 

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

 65. 

Suppose you apply a flame and heat one liter of water and raise its temperature by 40°C. If you instead transfer the same quantity of heat to 8 liters of water at the same temperature, what will be the temperature increase?
 

 66. 

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

 67. 

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

 68. 

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

 69. 

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

 70. 

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?
 



 
Submit          Reset Help