GCSE Physics 2.0

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Energy is never
used up but transferred between different energy stores and different objects
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Name 8 different energy stores
Thermal,Kinetic, Gravitational potential,Elastic Potential,Chemical,Magnetic,Electrostatic,Nuclear
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When a system changes...
Energy is transferred. It can be transferred into or away from the system, between different objects or between different types of energy stores
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Energy can be transferred by
Heating or by doing work
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Movement means
Energy in an object's kinetic energy store
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What is the formula for kinetic energy (j)(Ek)
1/2xMass(kg) xSpeedsquared (m/s^2)
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Raised objects
Store energy in Gravitational Potential Energy stores
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What is the formula for gravitational potential energy (Ep)
Mass(kg) X Gravitation field strength(N/kg) X Height (m)
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Falling objects
also transfer energy, when something falls, energy from its gravitational potential energy store to its kinetic energy store when thees no air resistance
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Stretching or squahing can
Transfer energy to Elastic Potential energy stores
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What is the elastic potential formula (Ee)
1/2 X Spring Constant(N/m) X Extension squared (m)
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Specific Heat Capacity is
How hard it is to heat something up.Its the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree celcius
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Materials that need to gain lots of energy in their thermal energy stores also
transfer alot of energy when they cool down. They can store alot of energy
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Whats the first step for investigating specific heat capacities
To investigate a solid material, you'll need a block of the material with two holes in it for the heater and thermometer to go into
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Whats the second step for investigating specific heat capacities
Measure the mass of the block, then wrap it in an insulating layer to reduce the energy transferred from the block to the surroundings.Then insert the thermometer and the surroundings
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Whats the third step for investigating specific heat capacities
Measure the initial temperature of the block and set the potential difference ,V, of the power supply to be 10V. Turn on the power supply and start a stop watch
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Whats the fourth step for investigating specific heat capacities
When you turn on the power, the current in the circuit (i.e the moving charges ) does work on the heater, transferring energy electrically from the power supply to the heater's thermal energy store.
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Still the fourth step
This energy is then transfered to the materials thermal energy store by heating, causing the materials temperature to increaseWhats the first step for investigating specific heat capacities
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Whats the fifth step for investigating specific heat capacities
As the block heats up, take readings of the temperature and current every minute for 10 minutes. You should find that the current doesnt change as the block heats up
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Whats the sixth step for investigating specific heat capacities
When youve collected enough readings turn off the power supply .Using your measurement ofthe current and the potential difference. You can use this to calculate the power supplied to the heater. using Power (P) =Potential Difference (V) x Current(I).
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Still sixth step
You can use this to calculate how much energy,E, has been transfered to the heate at the time of each temperature reading using the formula E=PT
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Whats the seventh step for investigating specific heat cappacities
If you assume that 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 temerature
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Whats the eighth step for investigating specific heat capacities
Then find the gradient of the graph by doing change in temperature divivided by change in energy
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Finally
You can repeat the experiment with different materials to see how their specific heat capacities compare
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What is the formula that links energy transferred to specific heat capacity
Change in thermal energy(Triangle E) =Mass kg(m) X specific heat capacity j/kg (C) X Temperature change trinangle theta (degrees celciuss)
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What is the conservation of energy principle
Energy can be transferred usefully,stored or dissipated,but can never be destroyed
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dissipitated energy means
wasted energy
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Power is
the rate of doing work
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What are the two formulas for power
Power = Energy transferred divided by Time & Work done divided by time
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Conduction occurs...
Mainly in solids
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What is conduction
Conduction is the process where vibrating particles transfer energy to neighbouring particles
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Energy is shared...
Across the kinetic energy stores of the particles in the object
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Convection occurs...
ONLY in liquids and gases
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What is convection
Convection is where energetic particles move away from hotter to colder regions
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What do radiators do
Radiators create convection currents
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How do radiators create convection currents
Heating a room with a radiator relies on creating convection currents in the air of the room.Energy is transferred from the radiator to the nearby air particles by conduction (the air particles collide with the radiator surface)
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Then what
The air by the radiator becomes warmer and less dense (as the particles move quicker). This warm air rises and is replaced by cooler air. The cooler air is then heated by the radiator.This warm air rises and is replaced by cooler air.
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Then what
This coole air is then heated by the radiator
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Other cards in this set

Card 2

Front

Name 8 different energy stores

Back

Thermal,Kinetic, Gravitational potential,Elastic Potential,Chemical,Magnetic,Electrostatic,Nuclear

Card 3

Front

When a system changes...

Back

Preview of the front of card 3

Card 4

Front

Energy can be transferred by

Back

Preview of the front of card 4

Card 5

Front

Movement means

Back

Preview of the front of card 5
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