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From Flashcardlet > Physics Unit 1 > Flashcards

Physics Unit 1 Flashcards

0
Q

Describe the process of condensation

A

When a gas cools, the particles in the gas slow down and lose kinetic energy meaning the attractive forces between the particles pull them closer together

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1
Q

Describe the “cooling effect” of evaporation

A

The fastest particles with the most kinetic energy are most likely to evaporate and when they do, the average kinetic energy of the remaining particles decreases meaning that the remaining liquid cools

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2
Q

Describe evaporation

A

If particles are travelling in the right direction and are travelling fast enough to overcome the attractive forces of other particles in the liquid, these particles near the surface of the liquid can escape and become gas particles

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3
Q

Give 4 things that would increase the rate of evaporation and explain why

A

Higher temperature (more particles have enough energy to escape)

Lower density (forces between particles are weaker so it easier for particles to escape)

Larger surface area (more particles close to surface so that they can escape)

Airflow over the liquid is greater (the lower the concentration of an evaporating substance already in the air it’s evaporating into, the higher the rate of evaporation, a larger airflow means the air around the liquid is replaced more quickly)

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4
Q

What is condensation?

A

When a gas turns to a liquid

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5
Q

What is evaporation?

A

When a liquid turns to a gas

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6
Q

Give 4 things that would increase the rate of condensation

A

Temperature of the gas is lower (average particle energy is lower)

Airflow is less (the concentration of the substance in the air is higher so the rate of condensation is higher)

Temperature of the surface the gas touches is lower

Density is higher (attractive forces between particles is higher)

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7
Q

What is the National Grid?

A

The system over the whole UK that transports electricity from where it’s produced to where it is needed

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8
Q

How do we increase the voltage of the electricity in the National Grid cables?

A

We use a step-up transformer that increases the voltage to 400000V and decreases the current

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9
Q

What are the 2 ways that the increasing demand for electricity could be dealt with?

A

Energy demands of consumers decrease (could be done by increasing energy efficiency)

Energy supplied to National Grid increased

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10
Q

Give 4 reasons that overhead cables would be chosen instead of underground ones

A

Low set up cost

Easy to access if there are faults

Easy to set up

Minimal disturbance to land

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11
Q

How is the voltage of the electricity decreased for use in homes?

A

A step-down transformer decreases the voltage and increases the current

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12
Q

What are the 2 types of National Grid cable?

A

Overhead cables (with pylons)

Underground cables

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13
Q

Why is the voltage so high in the National Grid cables?

A

To lower the current

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14
Q

Why does the current in the National Grid cables have to be so low?

A

A high current would mean that most of the energy is lost through heat in the cables

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15
Q

Give 4 reasons that underground cables would be chosen instead of overhead ones

A

Minimal maintenance needed

Hidden (don’t look ugly)

Not affected by weather

More reliable than overhead cables

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16
Q

What are the voltage in the National Grid cables?

A

400000V

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17
Q

What are the 4 disadvantages of solar cells?

A

Don’t generate electricity at night time

Initial costs are high

Too expensive to connect to National Grid

Not visually appealing

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18
Q

What are the 6 advantages of solar cells?

A

Can be very small for use in handheld devices

Can be used in remote places

No pollution

Very reliable in the summer

Running costs are very small

Can generate electricity for homes

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19
Q

What are the 4 problems with non-renewable energy methods?

A

Most release carbon dioxide adding to the greenhouse effect

Burning coal and oil releases sulphur dioxide which causes acid rain

Coal mining scars the landscape

Oil spillages can cause serious problems in mammals and birds that live around the sea

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20
Q

What are the 6 factors that are considered when setting up a power station? (Give explanation for each)

A

Set-up costs (renewable power stations usually cost more to set up than non-renewable)

Set-up time (nuclear take longest, gas are quickest, sometimes discussions can go on for years)

Reliability (non-renewable are always reliable, renewable usually relies on weather)

Running and fuel costs (renewable have lowest running cost because there is no fuel)

Environmental issues (atmospheric pollution, visual, nuclear can have big problems, resources like oil, noise, habitats)

Location (needs to be located near the source of energy, nuclear needs to be away from people and near water for cooling)

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21
Q

What are the 3 disadvantages of nuclear reactors?

A

Take a long time to set up

All costs are high

There is a possibility of nuclear disasters

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22
Q

What are the 3 advantages of nuclear power?

A

Produces a lot of electricity

No pollution

Nuclear fuel is fairly cheap

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23
Q

What are the 3 disadvantages of biofuels?

A

We still don’t know the full impact of biofuels on the environment

Large areas of forest have been destroyed to get to biofuels (loss of habitats, greenhouse effect)

Their use is limited to the amount of farmland that can dedicated to their production

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24
Q

How do solar cells work?

A

The solar cell is joined in series to some electrical components so that when light hits the solar cell, an electric current is produced

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25
Q

How does hydroelectric power work?

A

Water is stored in a dam and then all released so that it spins turbines so that electricity can be generated

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26
Q

How do biofuels produce energy?

A

The same way as fossil fuels

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27
Q

How does wind power work?

A

Wind spins large turbines which spin generators giving us electrical energy

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28
Q

What are the 3 advantages of tidal power?

A

No pollution

Reliable because they give us energy twice a day

Minimal running costs

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29
Q

How does geothermal power work?

A

Cold water is pumped underground where it is heated by hotrocks and pumped back up

The heat causes the water to become steam that drives a turbine

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30
Q

What is carbon capture and how does it work?

A

It is way of reducing carbon dioxide that leaves power stations

It is done by collecting the carbon dioxide before it leaves the power station and putting it into empty gas fields and oil fields under the sea

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31
Q

How does tidal power work?

A

The tide comes in and rises up to a pipe which it travels down and spins a turbine and is let out on the other side

The same happens when the tide goes out

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32
Q

What are the 4 types of non-renewable energy sources?

A

Coal, oil, natural gas and nuclear fuels (uranium and plutonium)

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33
Q

What are the 2 disadvantages of geothermal power?

A

Not many suitable locations

Expensive to set up (excavation included)

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34
Q

What are the 8 types of renewable energy sources?

A

Wind, waves, tidal, hydroelectric, solar, geothermal, food, biofuels

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35
Q

What are the 3 advantages of wave power?

A

No pollution

Low running costs

Don’t look particularly ugly

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36
Q

What are the 3 advantages of hydroelectric power?

A

No pollution because only rain water is used

Can provide immediate response to energy demand

Problems with reliability are rare (only in droughts)

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37
Q

What are the 3 advantages of energy from biofuels?

A

Can power some cars

Fuels can be solids, liquids or gases

They are produced using very eco-friendly methods

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38
Q

What are the 4 disadvantages of wind power?

A

They spoil the view (1500 turbines needed to replace power station)

Can be very noisy

No power when the wind stops

Initial costs are quite high

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39
Q

What are the 4 advantages of wind power?

A

Renewable

Electricity generated inside the turbine

No pollution

No permanent damaging to landscape because you can remove them and there will be no scarring

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40
Q

What are the 3 disadvantages of wave power?

A

You need a lot to produce enough energy

Hazard to boats

Unreliable because they depend on waves

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41
Q

What are nuclear power stations?

A

Where nuclear fission of uranium or plutonium produces the heat to make steam to drive a turbine

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42
Q

How does wave power work?

A

When a wave moves in, it goes into a pipe and forces air out of the pipe and into a turbine

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43
Q

What are the 3 disadvantages of hydroelectric power?

A

Requires flooding a valley

Loss of animal habitats

Initial costs are high

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44
Q

What are the 3 disadvantages of tidal power?

A

Prevents free boat access

Spoils the view

Altering habitats of wildlife

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45
Q

Describe how fuel power stations work

A

The fossil fuel is burned to convert its stored chemical energy to heat

The heat turns water to steam

The steam spins a turbine generating kinetic energy

The turbine spins a generator which generates electrical energy

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46
Q

What are the 3 advantages of geothermal power?

A

No environmental problems

Can heat builings directly

Very reliable (consistent)

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47
Q

How does pumped storage work?

A

At night, the spare energy is used to pump water back up to the top so that it can be released when their is high energy demand

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48
Q

What is the conservation of energy principle?

A

Energy can’t be created and destroyed but only transferred

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49
Q

What are the 2 formulas for calculating the cost of electricity?

A

Number of units used (kWh) = power (kW) * time (h)

Cost = no. of units * price per unit

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50
Q

What does “dissapated” mean?

A

When wasted energy (usually heat) becomes less concentrated (e.g. if heat spreads out)

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51
Q

What is a Sankey diagram?

A

A diagram that shows the input and output energies of a device and the device’s efficiency

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52
Q

Describe how you would draw a Sankey diagram

A

Show the energy in going to the left with the number of joules labelled

The energy wasted in different ways are boxes that go downwards and end with a point, label the type of energy and amount (the box widths are proportional to the input energy) (different boxes for different types of energy)

The energy still travelling to the left ends in a point and it is labelled “useful” and then the type of energy and also the amount of energy

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53
Q

Give 4 ways that access to electricity affects standard of living

A

Many types of energy in the home are convenient and can increase safety (eg. lights)

Refrigerators keep food fresh and keep vaccines cold. Without this, the area’s population can be drastically effected

Electricity is needed in hospitals (X-rays, diagnosis etc.)

Communications require electricity

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54
Q

What is a kWh?

A

The amount of energy used by a 1kW appliance left on for 1 hour

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55
Q

What is the main cause of inefficiency of devices?

A

Energy is wasted as heat

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56
Q

What are heat exchangers?

A

A device that reduces the amount of heat energy lost by collecting some of it back

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57
Q

What is potential energy?

A

Stored energy that is not being currently used

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58
Q

What are the 3 things you need to consider when buying an appliance?

A

Cost-effectiveness

Energy-efficiency

Whether the energy type needed is readily available

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59
Q

What is the formula that relates energy, time and power?

A

Energy = power * time

E = Pt

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60
Q

Describe how heat exchangers work

A

A cool fluid is pumped through the escaping heat

The fluid temperature increases and can be used for heating

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61
Q

What is the unit for energy used in homes?

A

Kilowatt-hours or kWh

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62
Q

What are the nine types of energy?

A

Electrical (flowing current)

Light

Sound

Kinetic (movement)

Nuclear potential (stored in nuclei of radioactive isotopes)

Thermal / heat

Gravitation potential

Elastic potential

Chemical potential (food, fuels etc.)

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63
Q

How do you calculate the power efficiency of a device?

A

Efficiency = useful power out / total power in

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64
Q

How do you calculate the energy efficiency of a device?

A

Efficiency = useful energy out / total energy in

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65
Q

What device is usually 100% efficient?

A

Electric heaters (heat is not waste energy)

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66
Q

What other liquid can be used in heaters and why is it used?

A

Oil because it has a high boiling point so you don’t have to worry about it evaporating at higher temperatures

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67
Q

How do electric storage heaters work?

A

They store the heat in concrete or bricks because they have a high specific heat capacity

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68
Q

What appliance needs a high specific heat capacity and why?

A

Materials used in heaters need a high specific heat capacity so that they can store large amounts of heat energy

69
Q

What is the specific heat capacity of water?

A

4200 Joules per kg per degrees C

70
Q

Why is water used for central heating systems?

A

High specific heat capacity to store heat

Liquid that can be pumped around a house easily

71
Q

What are electric storage heaters?

A

Heaters that store heat energy at night (electricity cheaper) and release it during the day

72
Q

How much energy is needed to heat 2kg of water from 10 degrees to 100 degrees C?

A

100 - 10 = 90
Energy = 2 * 4200 * 90

Energy = 756000J

73
Q

What is the formula for specific heat capacity?

A

E = mc(theta)

Energy transferred = mass * specific heat capacity * temperature change

74
Q

What is specific heat capacity?

A

The amount of energy needed to raise the temperature of 1kg of a substance by 1 degrees C

75
Q

Why is water preferable to oil in heaters?

A

Water has a much higher specific heat capacity

76
Q

What is U-value of a material?

A

A value that shows how fast heat can transfer through a material

The better the insulator, the lower the U-value

77
Q

What is payback time?

A

The amount of time that it takes for the amount of money saved to equal the cost of the insulation

78
Q

What is the unit of U-value?

A

Watts per square metre kelvin (W/m^2K)

79
Q

Describe the 5 methods of home insulation

A

Draught proofing - strips of foam and plastic around doors and windows that stop heat loss by convection

Loft insulation - a thick layer of fibreglass wool laid out across the loft floor and ceiling reducing heat loss by conduction and convection

Cavity wall insulation - foam squirted into the gap between the bricks reduces convection, conduction and radiation through the gap

Thick curtains - create an air gap between the window and room stopping hot air reaching the glass by convection. Conduction is also reduced

Hot water tank jacket - fibreglass wool around hot water tanks reducing conduction and convection

80
Q

What is a “cost-effective” method of insulation?

A

One that has a short payback time

81
Q

How do you calculate payback time?

A

Payback time (years) = initial cost / annual saving

82
Q

What is an “effective” method of insulation?

A

One that gives you a large annual saving (they save you a lot of money each year)

83
Q

Describe the arrangement, forces and energy in solids

A

Strong forces of attraction hold the particles in a fixed regular arrangement

The particles don’t have much energy so that can only vibrate about their fixed positions

84
Q

How does the surface type of the object affect its radiation?

A

Dark, matte surfaces absorb and emit much more infrared radiation than shiny, light surfaces

85
Q

Describe the convection in an immersion heater

A

Heat is transferred from the heater coils to the water by conduction (particle collisions)

The particles near the coils get more energy so they move around faster meaning there is more distance between them meaning that this water becomes less dense

The hotter water rises because it is less dense and displaced the colder water out of the way towards the heater coils

The cold water is heated by the coils and the hot water cools at the top of the immersion heater

This circuit repeats over and over again

86
Q

What factor affects the rate of conduction?

A

If the particles are closer together, the particles will collide more often and the rate of conduction will be higher

87
Q

Which states of matter does convection occur in?

A

Liquids and gases

88
Q

What is convection?

A

The process where more energetic particles move from the hotter region to the cooler region and take their heat energy with them

89
Q

Why don’t shiny, light surfaces absorb as much infrared radiation?

A

They reflect off most of the waves

90
Q

What is the simplest way that animals have evolved to deal with heat transfer?

A

Arctic foxes have small ears to prevent heat loss by radiation

Desert foxes have large ears that allow them to easily lose heat to keep them cool

91
Q

What are the 3 ways that heat energy can be transferred?

A

Radiation, conduction and convection

92
Q

How does temperature difference affect transfer of energy by heating?

A

The larger the temperature difference between a body and its surroundings, the faster energy is transferred by heating

93
Q

How does surface area affect the rate of heat energy transfer?

A

Heat is radiated from the surface of an object so the larger the surface area, the more infrared waves can be emitted from the object

94
Q

Describe the arrangement, forces and energy in gases

A

Almost no forces of attraction

Particles have more energy than in liquids and solids and are free to move in random directions at high speeds

95
Q

What is conduction?

A

The process where vibrating particles pass on their extra kinetic energy to neighbouring particles

This causes heat to spread throughout a solid

96
Q

How does surface area affect infrared radiation?

A

The larger the surface area, the higher the rate of infrared radiation because there are more places that the waves are emitted from

97
Q

What is kinetic theory?

A

The theory that describes how particles move in solids, liquids and gases and tells us that the energy of a particle is its movement or vibration (kinetic energy)

98
Q

In terms of heat radiation, what happens when an object is hotter than its surroundings?

A

The object emits more radiation than it absorbes as it cools

99
Q

How does volume affect rate of heat energy transfer?

A

If 2 objects at the same temperature have the same surface area but different volumes, the object with the smaller volume will cool quicker

This is because a higher proportion of the object will be in contact with its surroundings

100
Q

In terms of heat radiation, what happens when the object is cooler than its surroundings?

A

It absorbs more radiation than it emits as it warms up

101
Q

What causes metals to be good conductors?

A

Their free electrons can easily collide with each other and pass on the kinetic energy

102
Q

What is a convection current?

A

The way that, in convection, the hot water rises becomes cold and sinks and heats again and this circuits repeats again and again

103
Q

Which states of matter does conduction occur in?

A

Solids

104
Q

Describe the arrangement, forces and energy in liquids

A

The forces of attraction are weaker so the particles are still close together but they can move past each other

The particles have more energy than in a solid so they move in random directions at low speeds

105
Q

Describe how solar hot water panels make use of our knowledge of surface types and radiation

A

They contains water pipes under a black surface to heat the water in the pipes

Radiation from the Sun is absorbed by the black surface to heat the water in the pipes

106
Q

What happens to the particles of an object when you heat it?

A

The particles get more kinetic energy and vibrate or move faster

107
Q

How does the type of material affect the rate of heat energy transfer?

A

Conductors transfer heat much faster than insulators

If an object is in contact with a conductor, the heat will be conducted away much faster than if the object was in contact with an insulator

108
Q

What is heat radiation?

A

The transfer of heat energy by infrared radiation

109
Q

What makes a material an insulator?

A

When the material has larger spaces between its particles

110
Q

How do vaccum flasks prevent heat transfer?

A

The glass bottle is double-walled with a vaccum between the 2 walls preventing all conduction and convectiom through the sides

The bottle is supported with insulating foam minimising conduction to or from the outer glass bottle

The stopper is made of plastic and filled with cork or foam to reduce heat conduction

111
Q

What is the law of reflection?

A

Angle of incidence = angle of reflection

112
Q

What is the formula that links wavelength and frequency?

A

Wave speed (m/s) = frequency * wavelength

113
Q

What is the angle of reflection?

A

The angle between the reflected light ray and the normal

114
Q

What is wavelength?

A

The length of a full cycle of the wave (eg. from crest to crest) in metres

115
Q

Why can we see objects?

A

Because different light rays reflect off different objects and go into our retina

116
Q

Which types of wave are transverse?

A

All EM waves

Water ripples

117
Q

What is the angle of incidence?

A

The angle between the normal (imaginary line perpendicular to the surface) and the incident ray (the light ray approaching the mirror)

118
Q

How is a diffraction diagram drawn?

A

Lots of parallel vertical lines on the left side of the gap and lots of curved, spread out waves on the right

119
Q

What 2 factors affect the amount of diffraction?

A

The narrower the gap, the more the wave spreads out

The longer the wavelength, the more the wave spreads out

120
Q

Describe a diagram of refraction

A

The incident ray hits a glass block (or other more dense medium) and the ray bends towards the normal and is called the refracted ray

When the refracted ray emerges from the fender medium, it travels away at the same angle as the angle of incidence and is called the emergent ray

121
Q

What is a longitudinal wave?

A

A wave where the vibrations are parallel to the direction of energy transfer of the wave

122
Q

What does maximum diffraction look like?

A

The emerging waves look like semi-circles

123
Q

What causes refraction?

A

When the wave suddenly changed to a medium that has a different density, it changes speed accordingly and this changes the direction of the wave

124
Q

Describe how you draw a ray diagram for an image reflected in a mirror

A

Draw the reflected image on the other side of the mirror to the actual object (exactly as far away)

Draw an eye looking at the mirror from an angle

Draw the reflected ray coming from the virtual object to the top of the eye with an arrow on the ray to show this (dotted line for the virtual side of the mirror)

Draw the incident ray coming from the real object to the point where the reflected ray and mirror meet (add an arrow on the ray to show this)

Do the last 2 steps again but where the reflected ray meets the bottom of the eye

125
Q

Which types of waves are longitudinal?

A

Sound waves and ultrasound

Shock waves

126
Q

What happens when a wave hits the boundary at an angle?

A

The wave bends towards the normal

127
Q

What is refraction?

A

When a wave crosses the boundary between 2 substances, it changes direction

128
Q

What 4 things is the reflected image and why?

A

Same size as the object (it is as far behind the mirror as the object is in front)

Virtual (appears to be behind the mirror)

Upright

Laterally inverted (the left and right sides are swapped)

129
Q

What is frequency?

A

The number of complete waves passing a certain point every second measured in Hz (s^-1)

130
Q

What are the 3 ways that the direction of travel of a wave can be changed?

A

Reflection

Refraction

Diffraction

131
Q

What is transverse wave?

A

A wave where the vibrations are perpendicular to the direction of energy transfer of the wave

132
Q

What is amplitude?

A

The displacement of the wave from the rest (middle) to the crest (top) in metres

133
Q

What happens if the wave hits a boundary face on?

A

No refraction occurs

134
Q

What is diffraction?

A

If the wavelength of a wave is longer than the size of a gap that it has to go through, the wave will spread out when it emerges from the gap

135
Q

How does changing the surface affect the reflection of light rays off it?

A

An uneven surface causes light to reflect off in all directions so we can’t see a clear reflection

A smooth and shiny surface reflects all of the light rays in one direction meaning that we can see the reflected image

136
Q

What are the 2 types of waves?

A

Longitudinal

Transverse

137
Q

Describe how a camera works

A

Use a lens to focus visible light onto a light sensitive film or electronic sensor

The lens aperture controls how much light enters the camera (like a pupil)

The shutter speed determines how long the film or sensor is exposed to light

Varying the shutter speed and aperture can decide how much light is in a photo

138
Q

How are short radio waves sent to their destination?

A

You have be in a line of sight of the transmitter to receive the very short radio waves

139
Q

What are all the wave types in the electromagnetic spectrum in order? Give their wavelengths

A

Radio (1m to 10^4m)

Microwaves (10^-2m)

Infrared (10^-5m)

Visible light (10^-7m)

Ultraviolet (10^-8m)

X-rays (10^-10m)

Gamma rays (10^-12m)

140
Q

How are long radio waves sent to their destination?

A

They can diffract around hills and other similar obstacles so you don’t need a direct line of sight

141
Q

How do remote sensing satellites work?

A

Microwaves are used by the satellites to see through the clouds in order to monitor oil spills, icebergs etc.

142
Q

Describe how a satellite TV or mobile phone signal would travel to its destination

A

The transmitter would transmit the signal into space where it would be picked up by a satellite

The satellite would then transmit the signal to the TV or mobile phone

143
Q

Which type of wave is used for FM radio and TV?

A

The very short wavelength radio waves

144
Q

Why are people worried about how taking mobile phone calls could be dangerous to us?

A

If microwaves are travelling somewhere and they go through some water, the water would absorb them and then be heated up

If we hold a mobile phone close to our head while taking a call, the microwaves could be cooking the water in our cells and possibly damaging us

145
Q

How are medium-length radio waves sent to their destination?

A

They bounce off the ionosphere (electrically charged layer of the atmosphere) to get to their destination

146
Q

In communication, what are microwaves used for?

A

Satellite communication and mobile phones

147
Q

Give 2 ways in which infrared waves are used for communication

A

Sent by remote controllers in patterns to give instructions

IR and visible light are used to carry data over optical fibers by bouncing off the sides of the fibre

148
Q

What is the electromagnetic spectrum?

A

The continuous group of wave types that are all transverse and travel at the speed of light

Decreasing the wavelength would bring you up in the electromagnetic spectrum

149
Q

Why are microwaves used for satellite communication instead of radio waves?

A

The wavelength has to be short enough to pass through the Earth’s watery atmosphere to get to the satellites

150
Q

What are radio waves used for?

A

Communication including TV and FM radio transmissions

151
Q

What causes red-shift?

A

The doppler effect

152
Q

What is cosmic microwave background radiation?

A

Low frequency electromagnetic radiation coming from all parts of the universe

153
Q

What causes sound waves?

A

Vibrating objects

154
Q

Why is the big bang theory accepted over the steady state theory?

A

It is the only theory that explains the cosmic microwave background radiation

155
Q

How does big band theory explain the cosmic microwave background radiation?

A

Just after the big bang the universe was very hot so everything in the universe emitted high frequency radiation

As the universe expanded it cooled so the radiation dropped in frequency to microwaves

156
Q

Describe the steady state theory

A

The universe has always existed as it does now and always will do

The universe is expanding because matter is being created in the spaces as the universe expands

157
Q

What effect does changing the distance to a galaxy have in red-shift and why?

A

The further away the galaxy, the greater the red-shift because galaxies further away are moving away from us faster than nearer ones

158
Q

Describe the doppler effect

A

The frequency of a source moving towards you will seem higher so the wavelength will seem shorter

The opposite is true for an object moving away from you

159
Q

What type of wave does the doppler effect occur in?

A

Both transverse and longitudinal

160
Q

Describe red-shift

A

Different chemicals absorb different frequencies of light so each element produces a specific set of dark lines at the frequencies that it absorbs in the visible spectrum

The dark lines in light from distant galaxies are shifted towards the red side of the spectrum

This is red-shift

161
Q

How do we know that the universe is expanding?

A

The light from other galaxies is red-shifted

162
Q

What are the 2 problems with the big bang theory?

A

There are observations the theory can’t explain (universe’s expansion is increasing when it should be slowing)

No explanation for what caused the explosion

163
Q

Which type of wave is sound?

A

Longitudinal

164
Q

Describe the big bang theory

A

All matter and energy in the universe must have been compressed into a very small space and then it exploded from that point and started expanding

165
Q

What effect does changing the frequency of a sound wave?

A

The higher the frequency, the higher the pitch

166
Q

What effect does changing the amplitude of a sound wave have?

A

The higher the amplitude, the louder the sound

167
Q

How is the universe changing?

A

It is expanding and all galaxies are moving away from each other

168
Q

What are the 2 theories for the origin of the universe?

A

Big bang theory

Steady state theory

169
Q

Which states of matter does sound travel through the fastest and slowest?

A

Faster in solids than liquids

Faster in liquids than gases

170
Q

What else can sound waves do?

A

Diffract and refract

171
Q

Why do echoes happen?

A

They are reflected sound waves

From Flashcardlet (70 decks)

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