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8th Grade Physical Science Energy [3352]StudentClassDate

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

8th Grade Physical Science Energy /40

C. Input: Electricity

Output: Motion and sound only

D. Input: Electricity

Output: Motion, sound, and heat

3. Which of the following energy sources is the best example of a nonrenewable resource?

A. Co

al

B. Win

d

C. Wat

er

D. Sunlig

ht

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

B. Kerosene

heater

C. Flashlig

ht

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.

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.

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.

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

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.

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

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.

D. All of the materials will reach the same

temperature.

17.


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

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?

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

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. beak

er

B. lab

table

C. soluti

on

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.

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.


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.


B.

C.

D.


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.


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. condensat

ion

B. conducti

on

C. convecti

on

D. radiati

on

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.

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?

A.

B.

C.


D.

36. Which of the following is the best example of heat transfer by convection?

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?

A. conducti

on

B. convecti

on

C. evaporat

ion

D. radiati

on

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.

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.

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?


A.

B.

C.

D.


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.

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

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. fa

n

B. lam

p

C. radi

o

D. stov

e


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

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.

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.

In which direction does thermal energy begin to flow between the metal cubes?

A.

B.


C.

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.

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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