Physics Paper 1 (copy)

1. Elastic potential

2. Gravitational potential

3. Thermal

4. Electrostatic

5. Nuclear

6. Chemical

7. Kinetic

8. Magnetic

9. Light

10. Sound

1. Mechanically - force doing work

2. Electrically - work done by moving charges

3. Heating/Radiation - light, sound

When a current flows or by a force moving an object

E=1/2mv² Kinetic energy(J) = 0.5 x mass(kg) x speed²(m/s)

E=mgh G.P.E(J) = mass(kg) x gravitational field strength (N/kg) x height (m)

Energy lost from the g.p.e store = energy gained in the kinetic energy store

It causes some energy to be transferred to other energy stores e.g. the thermal energy stores of the object and the surroundings

E=1/2ke² E.P.E(J) = 0.5 x spring constant(N/m) x extension²(m)

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

E=mcθ Change in thermal energy(J) = mass(kg) x SHC(J/kg/°C) x temperature change(°C)

Energy can be transferred usefully, or stored or dissipated (wasted energy), but can never be created or destroyed

The rate of energy transfer, or the rate of doing work

1J of energy transferred per second

E=Pt Energy transferred(J) = power(W) x time(s)

W=Pt Work done(J) = power(W) x time(s)

The process where vibrating particles transfer energy to neighbouring particles Energy is transferred to thermal stores of the object - this energy is shared across the kinetic energy stores

A measure of how quickly energy is transferred through a material via conduction

Where energetic particles move away from hotter to cooler regions Energy is transferred to the thermal energy stores of the object and is shared across the kinetic stores

Convection currents

1. Energy is transferred from the radiator to the nearby air particles by conduction

2. The air by the radiator becomes warmer and less dense as the particles move quicker

3. The warm air rises and displaces the cooler air, which is then heated by the radiator

4. The previously heated air transfers energy to the surroundings - the air cools, becomes denser and sinks

Reduce frictional forces

Reduce the rate of energy transfer by heating

1. Cavity walls - made up of an inner and outer wall with an air gap in the middle - the air gap reduces the amount of energy transferred by conduction through the walls

2. Cavity wall insulators - the air gap is filled with foam also reduces energy transfer by convection in the wall cavity

3. Loft insulation - reduces convection currents being created in lofts

4. Double-glazed windows - air gap between two sheets of glass that prevent energy transfer by conduction through the windows

5. Draught excluders - reduce energy transfers by convection around doors and windows

1. Lubrication

2. Insulation

3. Making objects more streamlined

Useful output energy transfer divided by total input energy transfer

Useful power output divided by total power input

No

Thermal energy stores

They're made from a material with a low thermal conductivity - the thicker the walls, the lower the thermal conductivity, the slower the rate of energy transfer

Electric heaters - all the energy in the electrostatic energy stores is transferred to useful thermal energy stores

Non-renewable Cause acid rain Cause global warming Reliable currently - they are finite, so they will run out eventually Coal mining ruins the landscape Oil spillages cause serious environmental problems

Petrol and diesel from oil - non-renewable Coal (steam trains) - non-renewable Bio-fuels - renewable

Natural gas - non-renewable Coal - non-renewable Electric heaters - non-renewable Geothermal - renewable Solar water heaters - renewable Bio-fuels - renewable

Renewable Doesn't cause global warming Doesn't cause acid rain No pollution No permanent damage to the landscape Free - initial costs are high Very noisy Spoil the view Not always reliable

Renewable Doesn't cause acid rain Doesn't cause global warming No pollution Free - solar panels are expensive though Not always reliable

Renewable Doesn't cause acid rain Doesn't cause global warming Free Very little damage to the environment Not very reliable - can only happen in certain places and there aren't very many of them

Renewable Reliable Doesn't cause acid rain Doesn't cause global warming No pollution Provides an immediate response to high demand Free - initial cost is high Big impact on environment and possible loss of habitat

Renewable Doesn't cause acid rain Doesn't cause global warming Free - initial costs are high Not always reliable - waves die out when the wind drops Disturbs the seabed and habitats of marine wildlife Spoils the view Hazard to boats

Renewable Reliable Doesn't cause acid rain Doesn't cause global warming No pollution Free - initial costs are moderately high Spoils the view Alters the habitats of wildlife

Renewable Reliable Doesn't cause acid rain Carbon neutral Free Can cause global warming Loss of natural habitat from destruction of forests Cannot respond to immediate energy demands

Doesn't cause acid rain Doesn't cause global warming Reliable currently - finite Non-renewable High decommissioning costs Produces radioactive waste - no other pollution Nuclear waste is dangerous and hard to dispose of

1. Measure the mass of a block with two holes in it, then wrap it in an insulating layer (e.g. newspaper) to reduce the energy transferred from the block to the surroundings. Insert the thermometer into one hole and the heater into another

2. Measure the initial temperature of the block & set the potential difference of the power supply to be 10V. Turn on the power supply & start a stopwatch

3. When you turn on the power, the current in the circuit does work on the heater, transferring energy electrically from the power supply to the heater's thermal energy stores - this energy is then transferred to the material's thermal energy store by heating, causing its temperature to increase

4. As the block heats up, take readings of the temperature and current every minute for 10 minutes - the current shouldn't change

5. Turn off the power supply. Use the measurements of the current & the p.d. to calculate the power supplied to the heater, thus calculating how much energy has been transferred to the heater at the time of each temperature reading

6. If you assume all the energy supplied to the heater has been transferred to the block, you can plot a graph of energy transferred to the thermal energy store of the block against temperature

1. Boil water in a kettle. Pour some of the water into a sealable container to a safe level. Measure the mass of water in the container

2. Use a thermometer to measure the initial temperature of the water

3. Seal the container & leave it for 5 minutes. Measure this time using a stopwatch

4. Remove the lid & measure the final temperature of the water

5. Pour away the water & allow the container to cool to room temperature

6. Repeat this experiment, but wrap the container in a different material once it has been sealed. Ensure the mass of water is the same and so is the initial temperature each time

A system where neither matter nor energy can enter or leave

1. The population grew

2. People began to use electricity for more & more things

1. Appliances are becoming more efficient

2. We're more careful with energy use in our homes

1. Burning fossil fuels is damaging to the environment

2. Non-renewables will run out one day

3. Pressure from other countries & the public has led to targets being set e.g the UK aims to use renewable resources to provide 15% of the total yearly energy by 2020

Pressure being put on energy providers to build new power plants that use renewable resources to ensure that they don't lose business & money

1. Reliability - since some energy resources aren't that reliable, a combination of different power plants would have to be used - expensive

2. Money - building new power plants costs money, the cost of switching to renewable power will have to be paid & some people don't want to or can't afford to pay

3. Politics - companies and governments can't force people to change their behaviour

Energy is transferred - it can be transferred into/away from the system, between different objects in the system or between different types of energy stores

1. Large numbers of turbines would need to be built - takes up space & is expensive

2. Not always windy - the same amount of electrical power won't be produced every day

The flow of electrical charge

Amps

Voltage - it pushes the electric charge around the circuit

Volts

Anything that slows the flow down

Ohms

...the smaller the current that flows

Charge (coulombs) = current (amps) x time (seconds) Q=It

Potential difference (volts) = Current (amps) x Resistance (ohms) V=IR

...the greater the resistance

Series

Parallel

Yes - at a constant temperature, the current is directly proportional to the potential difference

Diodes and filament lamps

When the electrical charge flows through the lamp, it transfers some energy to the thermal energy stores of the filament which is designed to heat up. Therefore, the resistance, temperature and current all increase Resistance is directly proportional to temperature

Light Dependent Resistor - a resistant dependent on the intensity of light In bright light, the resistance decreases In darkness, the resistance is highest

A temperature dependent resistor In hot conditions, the resistance decreases In cold conditions, the resistance increases

It's shared between all the components

The current is the same in all components

The total resistance is the sum of all the resistances

The Pd is the same in all components

The current is shared between the components, therefore the total current is found by adding up the currents of all the components

If you have two resistors parallel, their total resistance is less than the resistance of the smallest of the two resistors

AC - Alternating current

DC - Direct Current

The current is constantly changing direction Alternating currents are produced by alternating voltages in which the positive and negative ends keep alternating

230V

50Hz (hertz)

Current is always flowing in the same direction Created by a direct voltage

Brown colour Bottom right of the three pin plug Provides the alternating pd from the mains supply - 230V Current flows in through this wire

Blue colour Bottom left of the three pin plug Completes the circuit and carries away current Electricity flows out through this wire Around 0V

Green and yellow colour Middle of the three pin plug Protects the wiring Stops the casing from becoming live Doesn't usually carry a current - only when there's a fault Around 0V

Energy transferred (J) = Power (W) x Time (s) E=Pt

1. 600 x (5 x 60) = 180,000J or 180kJ

2. 180,000J = 750W x t

3. t = 180,000J/750W

4. t = 240s = 4 minutes

...The less electricity an appliance uses in a given time, therefore it is cheaper to run

Energy transferred (J) = Charge flow (C) x Potential difference (V) E=QV

1. E=QV

2. E= 140C x 3V

3. E = 420J

Power (W) = Potential difference (V) x Current (A) P=VI

P=I²xR Power = current² x resistance

I=P/V I= 1000/230 I=4.3A

A giant system of cables and transformers that covers the UK and connects power stations to consumers

When it starts to get dark or cold outside When people get up in the morning When people come home from school or work

You lose loads of energy as the wires heat up and energy is transferred to the thermal energy stores of the surroundings

High potential difference and low current - decreases the energy lost by heating the wire and the surroundings

Friction - when two things rub against each other, electrons from one will rub off on to the other One material will have a positive static charge (e.g. acetate) and the other will have a negative static charge (e.g. polythene)

Electrons Positive charges never move - a positive charge is achieved when electrons move away

The potential difference between the object and the earth

When the electrons jump across the gap between the charged particle and the earth if the potential difference becomes too large

Usually fairly small (lightning is an exception)