Thermal Physics

Question 1

what is the formula for density

Answer 1

mass divided by volume

Question 2

what happens to density if mass stays the same and volume increases

Answer 2

density decreases

Question 3

what happens to density if mass stays the same and volume decreases

Answer 3

density increases

Question 4

what does kinetic theory of matter state

Answer 4

matter is made up of numerous tiny particles which are in constant random motion

Question 5

what are the forces of attraction in solids

Answer 5

strong forces of attraction between particles

Question 6

what are the forces of attraction in liquids

Answer 6

weaker forces of attraction than in solids

Question 7

what are the forces of attraction in gases

Answer 7

very weak forces of attraction

Question 8

how are particles arranged in solids

Answer 8

closely packed in a fixed regular arrangement

Question 9

how are particles arranged in liquids

Answer 9

closely packed in a random arrangement

Question 10

how are particles arranged in gases

Answer 10

far apart in a random arrangement

Question 11

how do particles move in solids

Answer 11

vibrate about fixed positions

Question 12

how do particles move in liquids

Answer 12

slide past one another

Question 13

how do particles move in gases

Answer 13

move freely and randomly at high speeds

Question 14

what happens to matter when it is heated

Answer 14

it expands

Question 15

what happens to matter when it is cooled

Answer 15

it contracts

Question 16

why does a ball expand when heated

Answer 16

thermal energy is absorbed particles vibrate more and move slightly apart so volume increases

Question 17

how does mercury behave in a thermometer when heated

Answer 17

it expands and rises up the tube

Question 18

why does coloured water fall in a tube when cooled

Answer 18

air in flask contracts due to cooling

Question 19

compare expansion of different states

Answer 19

gases expand more than liquids which expand more than solids

Question 20

what negative effects can expansion cause on roads

Answer 20

can cause cracks or tiles to pop out

Question 21

how are roads protected from expansion damage

Answer 21

expansion gaps are added

Question 22

how does expansion affect railway tracks

Answer 22

can cause tracks to warp

Question 23

how is laboratory glassware adapted to expansion

Answer 23

made from special glass that expands very little

Question 24

how are rivets used with thermal expansion

Answer 24

hot rivet contracts when cooled pulling steel plates together

Question 25

what is heat

Answer 25

energy transferred from a region of higher temperature to lower temperature

Question 26

what is temperature

Answer 26

measure of how hot or cold an object is

Question 27

what is si unit of heat

Answer 27

joule

Question 28

what is si unit of temperature

Answer 28

kelvin

Question 29

how should temperature be measured on a thermometer

Answer 29

to half the smallest division while avoiding parallax error

Question 30

what happens to particle motion as temperature increases

Answer 30

particles move faster and have higher average kinetic energy

Question 31

what happens to particle motion as temperature decreases

Answer 31

particles move slower and have lower average kinetic energy

Question 32

does temperature depend on mass or size of object

Answer 32

no

Question 33

do objects possess heat

Answer 33

no heat is energy in transit

Question 34

how is heat transferred between substances

Answer 34

from hotter to cooler substance

Question 35

what is conduction

Answer 35

transfer of heat through a medium without movement of the medium

Question 36

how is heat transferred in solids at particle level

Answer 36

particles vibrate and pass kinetic energy to neighbours by collision

Question 37

why are solids better conductors than liquids and gases

Answer 37

particles are more closely packed allowing more frequent collisions

Question 38

why are metals good conductors of heat

Answer 38

they have free electrons that transfer energy

Question 39

what is convection

Answer 39

transfer of heat by movement of fluid

Question 40

in which states of matter does convection occur

Answer 40

liquids and gases only

Question 41

how does convection current form in heated fluid

Answer 41

hot fluid expands becomes less dense and rises while cooler fluid sinks

Question 42

how does convection cool a room

Answer 42

cooler air sinks warm air rises setting up convection current

Question 43

what is radiation

Answer 43

transfer of heat by infrared waves without need for a medium

Question 44

what type of surfaces are good absorbers and emitters of radiation

Answer 44

dull rough black surfaces

Question 45

what type of surfaces are poor absorbers and emitters

Answer 45

shiny smooth silvery surfaces

Question 46

how does surface temperature affect radiation

Answer 46

higher surface temperature increases rate of radiation

Question 47

how does surface area affect radiation

Answer 47

larger surface area increases rate of radiation

Question 48

how to explain heat transfer by radiation

Answer 48

identify surface features and direction then state it is by radiation at faster or slower rate