s3 notes ut

Question 1

Heat

Answer 1

the enrgy transferred from a hotter object to another colder object

Question 2

Energy transfer

Answer 2

The amount of energy transfer due to a temperature difference

Question 3

thermal equilibrium

Answer 3

two objects reach the same final temperature (still energy transfer between the objects)

Question 4

Measure Energy

Answer 4

Joulemeter (J)
Kilowatt-hour meter (kWh)

Question 5

Power

Answer 5

How fast energy is transferred
The amount of energy transferred in 1 second

Question 6

The energy absorbed by an object when heated depends on

Answer 6

The increase in the temperature
the mass of an object
the material (specific heat capacity)

Question 7

Meaning of specific heat capacity

Answer 7

The energy required to heat up 1 kg of the object to increase its temperature by 1°C.
The energy released by 1 kg of the object when it decreases its temperature by 1°C

Question 8

Materials having a higher specific heat capacity means

Answer 8

More difficult to change temperature (both increase and decrease)
requires/ releases more energy to increase its temperature
Requires longer time to change temperature (providing that at the same rate)

Question 9

Heat capacity means

Answer 9

The energy required/ released to heat up that particular object to increase/ decrease its temperature by 1°C

Question 10

Objects having a higher heat capacity means
(3)

Answer 10

More difficult to change temperature (both increase and decrease)
Requires more energy to increase its temperature/ releases more energy to decrease ts temperature
Requires longer time to change temperature (provided that at the same rate)

Question 11

An object has high heat capacity if

Answer 11

The material has high specific heat capacity
Its mass is large

Question 12

Bunsen burner °C

Answer 12

1000°C

Question 13

Boiling point of water °C

Answer 13

100°C

Question 14

Melting point of water °C K

Answer 14

0°C 273K

Question 15

Absolute zero temperature °C K

Answer 15

-273°C 0K

Question 16

Thermometric properties (2)

Answer 16

The working principle of thermometers lies on thermometric properties.
Thermometric properties are properties which changes with temperature.

Question 17

Different types of thermometers

6

Answer 17

Liquid-in-glass thermometer, Resistance thermometer, Thermistor thermometer, Infra-red thermometer, rotary thermometer, liquid crystal thermometer

Question 18

Liquid-in-glass thermometer

Answer 18

Volume of liquid
(↑when temp↑)
Use: Laboratory use / measure body temperature

Question 19

Types of liquid in glass thermometer, working rang, ad and dis

Answer 19

Mercury-in-glass
Higher max temperature
Short response time
Mercury is toxic

Alcohol-in-glass
Lower min temperature
Not toxic
Longer response time

Question 20

Resistance thermometer

Answer 20

Resistance of metals
(Temp ↑
Resistance of metal ↑
Current ↓)

Ovens/ engines / observatory

Question 21

Thermistor thermometer

Answer 21

Resistance of semi-conductor
(Temp ↑
Resistance of semi-conductor ↓
Current ↑)

Measure body temperature/ electrical appliance

Question 22

Infra-red thermometer

Answer 22

Amount of infra-red radiation
(Temp ↑
Amount of infra-red ↑)

Measure body temperature

Question 23

Rotary thermometer

Answer 23

Degree of bending of the bimetallic strip
(Temp ↑
Bimetallic strip bends more)

Ovens/ freezers

Question 24

Liquid crystal thermometer

Answer 24

Colour of liquid crystal
Measure body temperature/ fish tank

Question 25

Clinical thermometer

Answer 25

Thermometers for measuring body temperature Clinical thermometer has to be accurate and sensitive

Question 26

Accurate

Answer 26

the measured temperature is equal to / very close to the actual temperature.

Question 27

Sensitive

Answer 27

the thermometer can show response (an observable change) to a slight change in temperature

Question 28

Sensitivity of thermometer | what makes it sensitive ## Footnote 2

Answer 28

Less °C per division → have a higher sensitivity The cross-section area of the glass tube is smaller → have a higher sensitivity

Question 29

Constriction

Answer 29

prevents the liquid level from falling back after the thermometer is taken out from our body

Question 30

Calibrating a liquid-in-glass thermometer (two fixing point)

Answer 30

Lower fixed point: 0°C= melting point of water (ice) HIgher fixed point 100°C= boiling point of water

Question 31

Calibrating a liquid-in-glass thermometer (steps)

Answer 31

The lower fixed point is marked by putting the thermometer into melting ice. The upper fixed point is marked by putting the thermometer into boiling water Divide the scale of the thermometer into equal parts

Question 31

Calculations on thermometers Graphical method (Assume linear relationship) | x,y

Answer 31

Y: length/cm (dependent variable) X: temperature/°C