Chapter 3

Question 1

What is the displacement method?

Answer 1

Irregular shaped materials are placed into a measuring cylinder of water. The increase in volume of water is the volume of object.

Question 2

What does irregular mean

Answer 2

the sides and angles of the shape are not equal

Question 3

How to calculate density

Answer 3

mass divided by volume

Question 4

How to calculate volume with density and mass

Answer 4

mass divided by density

Question 5

How to calculate mass with density and volume

Answer 5

density multiply volume

Question 6

What happens if you put something more dense than water on water

Answer 6

it will sink

Question 7

What happens if you put something less dense than water on water

Answer 7

It will float

Question 8

How do ships float on water

Answer 8

There are large spaces inside the ships that contains only air.The ship has a very high volume.

This means that the average density of the whole ship is less than the density of the water

Question 9

What happens if you put vegetable oil on water and why

Answer 9

The vegetable oil will float because it is less dense than water

Question 10

Why do balloons filled with helium float

Answer 10

helium is less dense than the air. Therefore balloons will float

Question 11

What unit is thermal energy measured in

Answer 11

Joules

Question 12

What is heat

Answer 12

heat is a measure of energy in particles

heat is the total thermal energy of the vibrating particles in an object

Question 13

There are 2 glasses water. There is a larger volume of water in one glass.What does this mean? and Why?

Answer 13

The glass with the larger value of water has greater total thermal energy than the glass with lower volume even when the temperatures are the same.

Because there are more particles, therefore the total thermal energy are higher

Question 14

What 2 things that temperature gives us information on

Answer 14

-The direction that thermal energy will be transferred
-The average energy of particles in an object

Question 15

What affects the transfer of thermal energy

Answer 15

The temperature difference between two objects

Question 16

Difference between heat and temperature

Answer 16

heat tells us the total energy of particles while temperature tells us about the average energy of the particles

Question 17

What does it mean when we say the temperature of the soup is higher than the water’s temperature

Answer 17

We are saying that the average energy of the soup is higher than the average energy of water particles

Question 18

What is the lowest temperature possible called

Answer 18

Absolute zero

Question 19

What is the temperature of absolute zero

Answer 19

-273C

Question 20

What does a sparkler not cause serious harm when a spark falls on your hand?

Answer 20

The mass of the spark is very small compared to the flame

Question 21

What do we mean when we say energy is conserved?

Answer 21

we mean that the total quantity of energy stays the same even when energy is stored, changed, transferred or even dissipated

Question 22

Can the total energy output be greater than the total energy input? Why?

Answer 22

No, this is because energy cannot be created

Question 23

What does energy being dissipated mean?

Answer 23

it means the energy spreads out into the surroundings and becomes less useful.

Question 24

Can energy be created?

Answer 24

NO

Question 25

Can energy be destroyed?

Answer 25

no

Question 26

What happens if you put your hands around a hot glass of drink

Answer 26

You will feel heat, this is because thermal energy moves from the drink, through the container and into your hands

Question 27

How does the movement of thermal energy work?

Answer 27

Thermal energy always moves from hotter places to colder places

Question 28

Why do your hands feel cold when you hold an ice?

Answer 28

The thermal energy from your hand transfer into the ice.

Question 29

What happens when you hold an ice for too long and why

Answer 29

You can damage your skin by holding ice for too long because your skin needs the correct quantity of thermal energy to function

Question 30

What makes metal being the best conductors of heat

Answer 30

the way of the particles are arranged. The electrons that are free to move in a metal help to pass along the vibrations

Question 31

What are poor conductors(good insulators) of heat?

Answer 31

Wood,plastics and fabrics such as wool and cotton

Question 32

What is the opposite of conductor

Answer 32

an insulator

Question 33

How do wooden spoons aid in cooking

Answer 33

they are good insulators. Therefore it makes the spoon comfortable to touch.

Question 34

How does the cooking pan's handle help with cooking

Answer 34

It is made from plastic which is a good insulator of heat, therefore it is comfortable to touch

Question 35

Why does conduction not work well in liquids

Answer 35

The particles just move around instead of just vibrating

Question 36

Why does conduction not work well in gases

Answer 36

the particles are far apart and the collisions are not very frequent

Question 37

Describe the process of conduction

Answer 37

The particles vibrates when heated, they push against the particles beside them and this causes the particles to vibrate more vigorously

Question 38

Imagine a gas or liquid that is heated at the bottom. The particles at the bottom will start to move faster and take up more space. THis part of the liquid or gas will become less dnese and start to float up through the colder, more dense parts. THis upward movement of warmer liquid or gas is called___

Answer 38

convection

Question 39

Explain how convection is useful in a cooking pan

Answer 39

the hot,less dense water rises to the top while the cooler water which are is more dense sinks to the bottom. This helps the water to get heated and cook faster as the colder water sinks to the bottom to get heated more easily.

Question 40

What is radiation

Answer 40

radiation is a type of wave we cannot see

Question 41

Thermal energy travels through the vacuum between the Sun and Earth. What is this type thermal energy transfer called?

Answer 41

radiation

Question 42

What does the term 'emit' means

Answer 42

to give out

Question 43

What is the difference between radiation and other ways of transferring energy?

Answer 43

It can pass through a vacuum, it does not need particles

Question 44

What are the best emitters and absorbers of radiation?

Answer 44

Objects that: are dull are black have a large surface area

Question 45

What are the worst emitters and absorbers of radiation?

Answer 45

Objects that: are shiny are white or silver have a small surface area

Question 46

What reflects radiation away

Answer 46

Shiny,white or silver surfaces

Question 47

How does vacuum flasks slow the transfer of thermal energy

Answer 47

By reducing conduction and radiation Inside a vacuum flask there is a glass bottle with a silver surface. The glass bottle is surrounded by vacuum. The silver surface of the bottle reflects thermal energy in the form of radiation back into the hot drink while the vacuum surrounding the bottle prevents conduction of thermal energy from the drink to the outside.

Question 48

What happens to the particles that remain when the particles with the highest energy escape from the water.

Answer 48

The average energy of the particles gets lowered

Question 49

What happens when water from your skins evaporates

Answer 49

the particles with the highest energy escape causing the water to cool. This causes cooling.

Question 50

What happens when the sweat on our body evaporates?

Answer 50

Its temperature drops.The thermal energy from the skin is then transferred to the cooler sweat.The process repeats

Question 51

How do air coolers use evaporation of water to cool air?

Answer 51

The air cooler contains a sponge that is soaked in water. A fan blows warm air from the room through the sponge. The warm air provides the thermal energy to evaporate the water and so thermal energy of the air decreases. This cools the air.

Question 52

What is the energy input and output when the ball held up in the air reaches the ground.

Answer 52

gravitational potential energy---> kinetic energy

Question 53

What is the useful and dissipated energy of television

Answer 53

Useful energy: light and sound energy Dissipated energy: heat energy

Question 54

What is the useful and dissipated energy of a light bulb

Answer 54

Useful energy: light energy dissipated energy: heat energy

Question 55

What is the useful and dissipated energy of a washing machine

Answer 55

Useful energy: kinetic energy dissipated energy: heat energy

Question 56

What is the useful and dissipated energy for an electric kettle

Answer 56

useful energy: heat , electrical energy dissipated energy: sound energy

Question 57

What is the useful and dissipated energy for a computer

Answer 57

useful energy: light and sound energy dissipated energy: heat energy

Question 58

What is the useful and dissipated energy for a hasir dryer

Answer 58

useful energy: thermal and kinetic energy dissipated energy: sound energy

Question 59

draw a Sankey Diagram with gravitational potential energy 6000J being transferred to energy dissipated to the environment 2500J and kinetic energy 3500J