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What is the formula for working out kinetic energy?

Kinetic energy = ½ x mass x speed^2

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What is the standard unit for mass?

Kilograms

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What is the standard unit for speed?

m/s (meters per second)

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What is the standard unit for kinetic energy?

Joules

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What is the standard unit for elastic potential energy?

Joules

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What is the standard unit for spring constant?

Newtons per metre (N/m)

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What is the standard unit for extension in the elastic potential energy equation?

Metres

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What is the formula for gravitational potential energy

G.P.E = mass x gravitational field strength x height

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What is the standard unit for gravitational field strength?

N/kg (newtons per kilograms)

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What is the standard unit for specific heat capacity?

Joules per kilogram per degree Celsius (J/KgoC)

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What is this the definition of: The amount of energy required to raise the temperature of 1kg of a substance by 1oC

Specific Heat Capacity

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What is defined as the rate at which energy is transferred or work is done?

Power

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What is the standard unit for power?

Watts

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What is the equation that links power, energy transferred and time?

Power =Energy transferred Time

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What is the equation that links power, work done and time?

Power =Work Done Time

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What is energy transferred the same as?

Work done

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An energy transfer of 1 joule per second is equal to a power of?

1 Watt

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If two electric motors both lift the same weight, the same height which will do it faster?

The more powerful one

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Energy can be transferred, stored or dissipated but cannot be

Created or destroyed

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In what type of system is there no net change to the total energy?

Closed

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How can we reduce unwanted energy transfers?

Lubrication

Use of thermal insulation

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How does increasing the thermal conductivity of a material affect the rate of energy transfer by conduction?

It increases it

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What factors affect the rate of cooling of a building?

Thickness of walls

Thermal conductivity of walls

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How do you work out efficiency from input and output energy?

Efficiency =Useful output energy transfer /Total input energy transfer

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How do you work out efficiency from power input and output

Efficiency =Useful power output /Total power input

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What are the three main types of fossil fuels?

Coal, Oil, Gas

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Name the main non-renewable energy resources?

Fossil fuels, Nuclear fuel

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Name 6 renewable energy resources

Biofuel, Wind, Hydro-electricity, Geothermal, Tidal, Solar, Water waves

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What type of resource is one that is being replenished as it is used?

Renewable

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What is required for an electrical charge to flow through a closed circuit?

A potential difference

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What is the flow of electrical charge?

electrical current

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What equation links charge flow, current and time?

Charge flow = Current x Time

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What is the standard unit for current?

Amps

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What is the standard unit for Charge flow?

Coulombs

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What is the standard unit for time?

Seconds

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What is the equation that links resistance, potential difference and current?

Potential difference = Current x Resistance

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What two things does the current flowing through a component depend on?

Resistance Potential Difference

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If you increase the resistance of a component what happens to the current, for a set potential difference

Decreases

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What is the standard unit for resistance?

Ohms

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What is the standard unit for potential difference?

Volts

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How are current and potential difference linked in an ohmic conductor

They are directly proportional

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Through which component is resistance constant?

Ohmic conductor

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How does the resistance of a filament lamp change as the temperature increases?

It increases

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How does the current flow in a diode?

only flows in one direction

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What can you tell me about the resistance in a diode?

Very high in the reverse direction

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How does the resistance of a thermistor change as the temperature increases?

It decreases

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How does the resistance of an LDR change as light intensity increases?

It decreases

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What could LDR's be used for

Switching lights on when it gets dark

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What could a thermistor be used for?

In a thermostat to control heating

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What is the current like in a series circuit?

the same everywhere

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What is the total resistance of two components in a series circuit?

It is the sum of the resistance of each component

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What is the total resistance of two resistors connected in parallel?

Less than the resistance of the smallest resistor

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What type of supply is the mains electricity in the UK?

AC

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What is the frequency of the domestic electricity supply in the UK?

50Hz

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What is the voltage of the domestic electricity supply in the UK?

230V

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What type of potential difference varies between a positive and negative value?

Alternating

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What type of potential difference is only found in the positive?

Direct

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How are most electrical appliances connected to the mains?

Using a three-cord cable

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What colour is the live wire?

Brown

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What colour is the neutral wire?

Blue

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What colour is the earth wire?

Green and yellow stripes

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What does the live wire carry?

The alternating potential difference from the supply

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What does the neutral wire do in a plug?

Completes the circuit

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What does the earth wire do in a plug?

It is a safety wire to stop an appliance becoming live

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What is the potential difference between the live wire and the earth?

230V

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What is the voltage of the neutral wire

At or close to 0V

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What is the voltage of the earth wire

0V, unless there is a fault

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What equation links power, potential difference and current?

Power = Potential difference x Current

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What equation links current, resistance and power?

Power = (Current)2 x Resistance

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What does the amount of energy an appliance transfers rely on?

How long the appliance is switched on for

The power of the appliance

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What is done when charge flows in a circuit?

Work

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What equation links energy transferred, power and time?

Energy transferred = Power x Time

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What equation links charge flow, potential difference and energy transferred

Energy transferred = charge Flow x Potential Difference

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What is the National Grid?

A system of cables and transformers linking power stations to consumers

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What is transferred from power stations to consumers using the National Grid?

Electrical power

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What are used to increase the potential difference from the power station to the transmission cables?

Step-up transformers

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What are used to decrease the potential difference for domestic use in the National Grid?

Step- down transformers

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What is the potential difference like in the transmission cables in the National Grid?

Very high

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What is the equation to work out density?

density= mass/volume

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Standard unit for density?

Kg/m³

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When a substance changes state what happens to the mass?

It stays the same

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Why is a physical change different from a chemical change?

In physical changes the material recovers its original properties if the change is reversed

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What do we call the energy stored inside a system by the particles that make up the system?

Internal energy

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What is the internal energy of a system made up of

The total kinetic and potential energy of all the particles

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