P1.1 The transfer of energy by heating processes and the factors that affect the rate at which the energy is transferred

Question 1

How can heat be transferred?

Answer 1

Radiation, Conduction and Convection

Question 2

What is heat radiation?

Answer 2

The transfer of heat energy by infra-red radiation

Question 3

What do conduction and convection involve?

Answer 3

The transfer of energy by particles

Question 4

What is conduction the main form of heat transfer in?

Answer 4

Solids

Question 5

What is convection the main form of heat transfer in?

Answer 5

Liquids and Gases

Question 6

What can infrared radiation be emitted by?

Answer 6

Solids, Liquids and Gases

Question 7

What do all objects emit and absorb?

Answer 7

Infrared Radiation

Question 8

The bigger the temperature difference…

Answer 8

The faster the energy is transferred by heating

Question 9

Where is infrared emitted from?

Answer 9

The surface of an object

Question 10

The hotter an object is…

Answer 10

The more infrared radiation it radiates in a given time

Question 11

An object hotter than its surroundings…

Answer 11

Emits more radiation than it absorbs

Question 12

An object cooler than its surroundings…

Answer 12

Absorbs more radiation than it emits

Question 13

Which surfaces absorb and emit infrared radiation the best?

Answer 13

Dark, matt surfaces

Question 14

Which surfaces are poor absorbers and emitters of infrared radiation?

Answer 14

Light, shiny surfaces

Question 15

What do light, shiny surfaces do to infrared radiation?

Answer 15

They reflect it

Question 16

What forces hold a solid together?

Answer 16

Strong forces of attraction

Question 17

What arrangement does a solid have?

Answer 17

Regular and fixed

Question 18

How much energy do particles in a solid have?

Answer 18

Not much

Question 19

How do the particles in a solid move?

Answer 19

They vibrate around fixed positions

Question 20

What forces hold a liquid together?

Answer 20

Weaker forces of attraction

Question 21

What arrangement do the particles have in a liquid?

Answer 21

An irregular arrangement, the particles are close together but can move past each other

Question 22

How much energy do particles in a liquid have?

Answer 22

More energy than particles in a solid

Question 23

How do the particles in a liquid move?

Answer 23

In random directions at low speeds

Question 24

What forces hold a gas together?

Answer 24

Almost no forces of attraction

Question 25

What arrangement do the particles in a gas have?

Answer 25

None

Question 26

How much energy do particles in a gas have?

Answer 26

More energy than liquids and solids

Question 27

How do the particles in a gas move?

Answer 27

In random directions at high speeds, colliding into each other

Question 28

What happens when you heat a substance?

Answer 28

You give the particles more kinetic energy

Question 29

What is the process of conduction?

Answer 29

Where vibrating particles pass on their extra kinetic energy to neighbouring particles

Question 30

Why is conduction faster in solids?

Answer 30

Because the particles are closer together and therefore will collide more often and pass energy between them

Question 31

Why are metals good conductors?

Answer 31

Because of their free electrons which move through the metal colliding with particles and transferring energy

Question 32

When does convection occur?

Answer 32

When an area gets hotter its particles move further apart, this makes that area less dense and lighter than its surroundings so it rises. When it starts to cool the particles move closer together and it falls

Question 33

What is condensation?

Answer 33

When a gas cools turns into a liquid due to the particles losing kinetic energy

Question 34

What is evaporation?

Answer 34

When particles in a liquid with the most kinetic energy overcome the forces of attraction and escape turning the liquid into a gas

Question 35

What affects the rate of evaporation?

Answer 35

Temperature (faster if higher) Density (faster if lower) Surface Area (faster if larger) Airflow (faster if greater)

Question 36

What affects the rate of condensation?

Answer 36

Temperature (faster if lower) Temperature of the surface that the gas touches (faster if lower) Density (faster if higher) Airflow (faster if less)

Question 37

The bigger the surface area...

Answer 37

The more infrared waves that can be emitted/absorbed by the surface, so the quicker the transfer of heat

Question 38

The smaller the volume...

Answer 38

The quicker the object will cool

Question 39

What other factors affect the rate of heat transfer?

Answer 39

The type of material, the nature of the surface with which the object is in contact

Question 40

The bigger the temperature difference between an object and its surroundings...

Answer 40

The faster the rate at which the energy is transferred by heating

Question 41

What is the U-Value?

Answer 41

the rating to determine how good an insulator something is. The lower the u-value the better it is at insulating

Question 42

What is Payback time?

Answer 42

The amount of time it takes to save back on your energy bills the money spent on the insulation

Question 43

How do solar panels work?

Answer 43

They contain water that is heated by radiation form the sun

Question 44

What is specific heat capacity?

Answer 44

The amount of energy needed to raise the the temperature of a 1kg substance by 2 degree

Question 45

What is the word equation for specific heat capacity?

Answer 45

Energy = Mass x specific heat capacity x temperature range