2.5: Energy transfer; Radiation

REVIEW;

Good morning! Do you remember these ideas from the previous lesson?

• Conduction?

• Convection?

Answer these (few) review questions to jog your memory?

Multiple Choice

True / False; Conduction and convection are both heat transfer processes

• TRUE

• FALSE

Multiple Choice

Which of the two processes requires direct contact for heat transfer?

• Conduction

• Convection

Multiple Choice

Which of the two processes doesn't require direct contact for heat transfer?

• Conduction

• Convection

Multiple Choice

Which of the two processes happens through vibration of particles?

• Conduction

• Convection

Multiple Choice

Which of the two processes happens by means currents?

• Conduction

• Convection

Multiple Choice

Which of the two processes transfers heat energy from hot to cold areas?

• Conduction

• Convection

• Both

• None

Multiple Choice

Which of the two processes transfers happens in solids only?

• Conduction

• Convection

• Both

Multiple Choice

Which of the two processes transfers happens in fluids only?

• Conduction

• Convection

• Both

Multiple Choice

Which of the two processes transfers happens faster?

{Exira credit; Explain why to your teachers - think about the particles in the materials)

• Conduction

• Convection

• Both

2.5 Energy transfer; Radiation

Lesson objectives;

• Describe some sources of infrared radiation

• Explain how energy is transferred by radiation

Multiple Choice

What type of image is this?

• Thermal infrared image

• Dark train image

• Inverted light image

Multiple Choice

Use page 148 to answer;

What is (thermal) radiation?

• Very hot things

• Burning coal

• Heat energy emitted from hot objects/sources

Multiple Choice

YES / NO; Page 148

You need some particles to transfer heat energy by radiation

• YES

• NO

Multiple Select

Page 148;

Which of the following are true? (Select all that apply)

• Light and infrared energy reach the earth from the sun

• Light and infrared energy travel through space

• Space is a vacuum

• There are no particles in a vacuum

Multiple Choice

TRUE of FALSE? (Page 148)

All objects, including me, give out (emit) infrared radiation

• TRUE

• FALSE

Multiple Choice

Page 148;

The type of radiation emitted by an object depends on;

• Their temperature

• The type of surface

Multiple Choice

Page 148;

The amount of radiation emitted per second depends on;

• The temperature of the object

• The type of surface

Multiple Select

Which of the following are sources of infrared radiation? (If uncertain, use google 😎, or ask me)

• ME

• YOU

• ICE CUBES

• TREES

Multiple Choice

Page 148; How does your skin detect infrared radiation from the sun?

• The skin turns pale blue

• The skin gets warmer under the sun

• The skin hairs stand up

• The skin doesn't detect radiation because it's not a machine

Multiple Choice

Page 149; A camera that absorbs infrared and produces an image is called;

• Canon Megapixels

• Kodak multicolor infrared

• Infrared Image generator

• Thermal imaging camera

Multiple Choice

Page 149;

How does a thermal imaging camera work?

• Hotter areas are shown as redder in the image

• It removes all the light from the image

• The dark colors in the image are false

Multiple Choice

TRUE OR FALSE;

During COVID, remote thermometers were used to check your temperature at the gate. These thermometers use infrared sensors.

• TRUE

• FALSE

Multiple Select

Why do marathon runners wear foil blankets after a race? Select all true statements.

• Their bodies lose heat quickly

• The foil reflects infrared heat back to their bodies

• Foil prevents body temperature from falling too quickly

• They want to stand out while using cheap materials

Multiple Choice

Page 148; State what happens when infrared hits a shinny surface.

• It's absorbed

• It's reflected

Multiple Choice

You feel hotter when you wear darker clothes because;

• Dark colors reflect infrared radiation

• Dark colors absorb infrared radiation

Multiple Select

If you wash and hang clothes on a line, which one's are more likely to dry faster? Why? Select two answers.

• Dark ones

• Light ones

• Dark clothes absorb infrared radiation, white & shiny clothes reflect infrared radiation

• Dark clothes reflect infrared radiation, white & shiny clothes attract infrared radiation

Multiple Choice

Why are houses painted white in hot countries?

• To look nice

• White is the color of royalty 😎

• White absorbs infrared radiation

• White reflects the infrared heat away from the house

Multiple Choice

Look at the purple table on page 148 of your textbook.

What is the purpose of the experiment? (title)

• Effect of can size on time of cooling

• Effect of color on the time taken for the can to cool down

• Temperature drop

• Student observations about heat loss of different cans

Multiple Select

The outliers from this data are; (Select two answers)

• 5

• 23

• 10

• 18