8th Grade Physical Science Energy [3352]
Student
Class
Date
1. The transfer of heat that occurs from the movement of liquids or gases of different densities causes
convection currents. Which of the following is an example of heat transfer by convection?
A. A hot wood stove heats an entire room
B. The handle of a pot that is being heated becomes warm.
C. A teaspoon in a glass of hot tea becomes warm.
D. The coils of a toaster becomne red.
2. Which of the following represents the input/output energy forms for a stereo system?
A. Input: Motion
Output: Sound only
B. Input: Motion
Output: Sound and heat only
C. Input: Electricity
Output: Motion and sound only
D. Input: Electricity
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Output: Motion, sound, and heat
3. Which of the following energy sources is the best example of a nonrenewable resource?
A. Coal
B. Wind
C. Water
D. Sunlight
4. An insulated bottle keeps a cold liquid in the bottle cold by
A. destroying any heat that enters the bottle
B. keeping cold energy within the bottle
C. trapping dissolved air in the liquid
D. slowing the transfer of heat into the bottle
5. Which of the following is designed to convert energy into mechanical work?
A. Electric fan
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B. Kerosene heater
C. Flashlight
D. Baking oven
6. Household appliances convert electricity into one or more different forms of energy. An electric fan can
best be described as converting electricity into
A. heat energy only
B. heat energy and sound energy only
C. heat energy, sound energy and mechanical energy only
D. heat energy, sound energy, mechanical energy, and chemical energy
7.
The sequence of energy changes shown in the diagram explains which event?
A. A flashlight is on.
B. A candle burns.
C. Gasoline burns to power a car.
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D. Electric current runs a refrigerator.
8. A student rapidly rubs the palms of both hands together. Which sequence correctly describes the energy
transformations that occur?
A.
B.
C.
D.
9. An incandescent light bulb is shown below.
A typical incandescent light bulb has an energy efficiency of about ten percent. What is the meaning of
this statement?
A. Ten percent of the bulb's light energy becomes heat energy.
B. Ten percent of the energy used by the bulb becomes light energy.
C. The bulb uses ten percent less electrical energy than other bulbs.
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D. The bulb will save ten percent on electrical energy costs per year.
10. A cup of water at 40°C and a cup of water at 5°C are left on a table. Which graph correctly shows the
temperature of the two cups of water as time passes?
A.
B.
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C.
D.
11. When a steel block at 100°C is placed on top of a copper block at 20°C, the thermal energy of the copper
begins to increase. Which of the following is the source of this increase in energy?
A. the work done by the molecules within the copper
B. the work done by the interaction of the two metals
C. heat flowing by means of conduction
D. heat flowing by means of radiation
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12. A container of cold water is dumped into a larger container of hot water. It is mixed and then left alone
for a long time interval. The water temperature is found to
A. randomly vary from region to region in the container.
B. be uniform throughout the container.
C. fluctuate at all positions in the container.
D. be greater at the bottom of the container.
13.
Which of the following statements best describes the energy transformation that occurs when a log
burns?
A. Mechanical energy changes to chemical energy.
B. Chemical energy changes to heat and light energy.
C. Heat and light energy changes to chemical energy.
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D. Mechanical energy changes to heat and ligth energy.
14. A log was burned in a fireplace. Which statement is true about the leftover ashes when they are
compared to the original unburned log?
A. The ashes have more mechanical energy than the unburned log.
B. The ashes occupy the same amount of space as the unburned log.
C. The ashes have less chemical energy than the unburned log.
D. The ashes have the same molecular structure as the unburned log.
15. A local recreation center has received funding to build a swimming pool. After construction, the center
will be responsible for all costs associated with pool operation. As a result, the center must consider a
variety of design options, including pool size, location and heating.
Where should hot water enter the pool to better heat the water?
A. A
B. B
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C. C
D. D
16. The diagram shown represents a closed energy system. The system contains equal masses of air, copper,
granite, and water in a perfectly insulated container. The temperatures were taken at the time the
materials were placed in the closed system.
How will the temperatures of the materials change over an extended period of time?
A. The temperature of each material will decrease.
B. The temperature of each material will remain constant.
C. Warmer materials will get warmer and cooler materials will get cooler.
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D. All of the materials will reach the same temperature.
17
.
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Which flowchart best summarizes heat transfer to the cooking chicken?
A. Electricity turns to heat → currents of radiation swirl around the chicken → the inside of the
chicken warms up →heat spreads throughout the chicken
B. Electricity turns to heat → air in the oven heats up and the molecules move faster → air moleucles
bump into the chicken → moleules in the chicken move faster
C. Electricity turns to heat → heat flows through the metal oven shelf into the chicken pan → heat
flows from the pan into the bottom of the chicken → heat flows into the rest of the chicken
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D. Electricity turns to heat → heat causes the air molecules to change shape → the changed air
molecules cause the chicken moelcules to change shape → the changed chicken molecules release
hele
18. When an electric fan is running, most of the incoming electrical energy changes into which kind of
energy?
A. heat energy
B. light energy
C. mechanical energy
D. sound energy
19. When a light bulb is turned on, energy changes from one form to another. Which of the following best
describes this change?
A. sound energy to light energy
B. nuclear energy to light energy
C. electrical energy to light energy
D. magnetic energy to light energy
20. A flowing stream contains water at 18°C. Cans of soft drinks at 28°C are lowered into the
stream. Which of the following will most likely occur?
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A. The soft drink cans will absorb cold energy from the stream's water.
B. The cans will cool until their temperature is the same as the stream's.
C. The temperature of the soft drinks will not change since the cans are sealed.
D. The temperature of the cans will decrease to freezing as long as the stream is flowing.
21. An incomplete energy transformation diagram is shown below.
Wind turns a turbine and creates electricity. Which types of energy complete this energy transformation
diagram for the turbine?
A. X: solar energy Y: mechanical energy
B. X: mechanical energy Y: nuclear energy
C. X: chemical energy Y: solar energy
D. X: nuclear energy Y: chemical energy
22. Which of the following is an example of heat transfer by conduction?
A. a whole metal spoon getting hot when one end is in hot soup
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B. the inside of a car in the sun getting very hot
C. a tar road getting hotter in the sun than a concrete sidewalk
D. a fireplace fire heating a room on a cold day
23. Four containers of water with different temperatures are placed on a table as shown below. The
temperature of the room is 25°C.
After four hours, which beaker of water will have exchanged the most heat energy with the environment?
A. W
B. X
C. Y
D. Z
24. A student in a laboratory transfers a beaker containing a hot solution from the lab table to a cool water
bath. Which of the following parts of the system experiences an increase in heat energy?
A. beaker
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B. lab table
C. solution
D. water bath
25. The surface of a heated metal object measures 120°C. It is dropped into a bucket filled with water
measuring 10°C. Which of the following is most likely to occur?
A. Both the water and metal will adjust to the same temperature below 10°C.
B. The water and metal will adjust to different temperatures above 120°C.
C. The water will remain the same temperature, but the metal will cool to 10°C.
D. The water and metal will adjust to the same temperature between 10°C and 120°C.
26. A pot of cold water was heated on a stove until the water boiled. Which of the following best explains
why the water was able to boil?
A. The hot stove absorbed cold from the pot.
B. The cold water absorbed heat from the pot.
C. The hot stove gave off heat to the surrounding air.
D. The cold water gave off cold to the surrounding air.
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27. Four different-colored blocks are placed outside in bright sunlight. The blocks are identical except for
color. The diagram below shows the amount of light reflected from each block.
Which block will increase in temperature most rapidly?
A. block 1
B. block 2
C. block 3
D. block 4
28. Which of the following is the main reason water at the surface of the ocean is warmer than water at the
bottom of the ocean?
A. Water at the bottom of the ocean contains more dissolved solids.
B. Water at the surface of the ocean absorbs more energy from the Sun.
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C. Friction is created by fast moving currents at the surface of the ocean.
D. Wave action transfers heat from the bottom of the ocean to the surface.
29. A teacher put one test tube of 50°C liquid and one test tube of 10°C liquid into a 20°C water bath, as
shown in the diagram below.
Which of the following diagrams best represents the directions that heat will mvoe when the test tubes
are placed into the water bath?
A.
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B.
C.
D.
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30. The illustration below represents an experiment in which a hot object is added to a container of water at
room temperature.
The water is continuously stirred while the hot object is immersed in it. Which of the following graphs
best shows the temperature changes that follow?
A.
B.
C.
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D.
31. When one end of a short metal bar is heated, the opposite end will eventually become hot. Which of the
following processes transfers the heat through the bar?
A. condensation
B. conduction
C. convection
D. radiation
32. A heated rock is placed in a container of water that is cooler than room temperature. Which of the
following statements best describes what happens?
A. Cold is removed from the container of water until the rock, the container, and the water all reach
the same final temperature.
B. The heated rock loses heat to the container of water until the rock, the container, and the water all
reach the same final temperature.
C. The heated rock loses heat to the container of water until the rock, the container, and the water each
reach a different final temperature.
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D. Cold is removed from the container of water until the rock, the container, and the water each reach
a final temperature lower than their original temperatures.
33. Which of the following statements best explains why there is no change in temperature once thermal
equilibrium between two objects in contact is reached?
A. Heat can flow between two objects in contact.
B. Heat does not flow between objects in contact at the same temperature.
C. Heat does not flow spontaneously from a cooler object to a warmer object.
D. Heat flows by conduction, convection, and radiation when the temperatures are the same.
34. Which of the following is an example of heat transfer by conduction?
A. sunlight heating a floor
B. an electric stove heating an iron pan
C. a wood stove heating nearby objects through electromagnetic waves
D. an electric heater heating air, which rises and is replaced with cooler air
35. Which of the following objects transfers its energy primarily by radiation?
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A.
B.
C.
D.
36. Which of the following is the best example of heat transfer by convection?
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A.
B.
C.
D.
37. An architect knows that a home receiving a lot of exposure to the Sun will benefit from the heating
effects of sunlight if there is a lot of glass in the home's design. By which of the following methods will
sunlight heat the home?
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A. conduction
B. convection
C. evaporation
D. radiation
38. The diagram below represents an electric furnace.
Cold air enters through the cold air return and hot air is blown out the supply duct. Which of the
following statements correctly describes heat transfer within the furnace?
A. The furnace transfers heat by condensation.
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B. The furnace transfers heat through combustion.
C. The furnace decreases heat transfer by radiation.
D. The furnace increases heat transfer by convection.
39. A student touches a metal sink with her finger and notices that her finger feels cold. Which of the
following statements explains this observation?
A. Heat energy flows from the student's finger to the metal sink.
B. Heat energy flows from the metal sink to the student's finger.
C. The student's finger was originally at the same temperature as the sink.
D. The student's finger was originally at a lower temperature than the sink.
40. In which of the following examples is heat transferred primarily by radiation?
A. A fan blows warm air around a room.
B. A hot water bottle warms a person's feet.
C. Water vapor from a shower warms the room.
D. A spoon held near the side of a flame gets warm.
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41. The drawing below shows a person sitting on a sofa in front of a fireplace.
Which of the following are the primary modes of heat transfer from the fire in the fireplace to the
person?
A. radiation and convection
B. radiation and condensation
C. convection and conduction
D. conduction and condensation
42. The drawings below show four half-filled 12-oz. plastic coffee cups, containing coffee intially at
80°C. In which cup will the coffee cool most quickly?
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A.
B.
C.
D.
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43. An iron bar is placed in a flame, as shown below, and heated until the end glows.
The other end of the iron bar soon becomes hot, too. Which of the following statements best describes
what happens?
A. A convective flow of energy is set up inside the iron bar.
B. Energy is conducted from atom to atom along the length of the iron bar.
C. Radiation moves through the iron bar and is absorbed by the end not in the flame.
D. Air heated by the flame radiates down the iron bar and heats the end not in the flame.
44. Which of the following statements best explains how heat flows by conduction?
A. A large mass of air begins to move faster.
B. Energy is transferred by electromagnetic waves.
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C. Energy is transferred from molecule to molecule.
D. A large mass of warm air rises, replacing the cooler air above.
45. The illustration below shows two heat lamps being used to keep food warm.
In which way does most of the heat from the lamps reach the food?
A. by conduction
B. by evaporation
C. by radiation
D. by resistance
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46. During the construction of a house, which of the following actions would most likely minimize heat loss
due to conduction?
A. installing a forced hot air heating system
B. increasing the number of south-facing windows
C. making sure all exterior doors are properly sealed
D. insulating exterior walls to attain the highest R-value
47. Foam weather stripping is often placed in the frames of doors and windows in a home. What effect does
this weather stripping have?
A. The weather stripping increases heat transfer by radiation.
B. Heat is conducted quickly through the weather stripping.
C. The weather stripping reduces heat loss due to convection.
D. Heat can transfer through the weather stripping due to reflection.
48. Electrical energy may sometimes be converted to mechanical energy.
Which of these appliances converts electrical energy into mechanical energy?
A. fan
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B. lamp
C. radio
D. stove
49. A metal pot with hot soup in it is placed on a cool stone countertop, as shown in the diagram below.
The numbered arrows show the transfer of heat from the pot of soup to the surrounding
environment. Which list identifies each method of heat transfer?
A. 1 - conduction; 2 - convection; 3 - radiation
B. 1 - convection; 2 - conduction; 3 - radiation
C. 1 - radiation; 2 - radiation; 3 - convection
D. 1 - convection; 2 - conduction; 3 - conduction
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50. How does ice cool a warm drink?
A. Cold flows from the ice to the drink.
B. Heat flows from the ice to the drink.
C. Cold flows from the drink to the ice.
D. Heat flows from the drink to the ice.
51. A family replaced the insulation in the attic and the weather stripping and caulking around the windows
and doors. What is the best reason for making these changes to their house?
A. to conserve energy when heating and cooling their home
B. to keep noises in the neighborhood from entering their home
C. to prevent unwanted insects from coming into their home
D. to allow fressher air to move into and out of their home
52. The pictures below show pairs of metal blocks and their temperatures. Which of these correctly shows
the direction that heat energy will move?
A.
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B.
C.
D.
53. Which of these is an example of chemical energy being converted into thermal energy?
A. water boiling
B. butter melting
C. candles burning
D. steam condensing
54. Three metal cubes are heated to the temperatures shown and placed in contact with one another on a
nonconducting surface. The picture below shows the cubes next to one another and their temperatures.
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In which direction does thermal energy begin to flow between the metal cubes?
A.
B.
C.
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D.
55. Three identical blocks are pushed together. The starting temperature of each is shown.
Which traces the transfer of thermal energy among the blocks?
A. X ← Y → Z
B. X→ Y → Z
C. X → Y ← Z
D. X ← Y ← Z
56. The illustration below shows a student bending a piece of wire back and forth at a single point X. The
wire's temperature rises noticeably at point X.
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Which of the following best describes the source of the temperature increase?
A. Some of the wire's mass is transformed into heat energy as the wire is bent.
B. Some of the kinetic energy is transformed into heat as the wire is bent.
C. The bending transfers potential energy to the wire, heating it.
D. The bending causes a current that heats the wire.
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