paper 1 topics
what is a system?
an object or a group of objects; if anything changes in a system, energy is transferred between its stores or to the surroundings
what is a closed system?
where no energy can escape to or enter and the total energy never changes
what are the energy stores?
- kinetic energy
- gravitational potential energy
- elastic potential energy
- thermal/internal energy
- chemical energy
- nuclear energy
- magnetic energy
- electrostatic energy
what is kinetic energy?
the energy an object has because its moving
what is gravitational potential energy?
the energy an object has because of its height above the ground
what is elastic potential energy?
energy an elastic object has when its stretched or compressed
what is thermal/internal energy?
energy an object has because of its temperature [the total kinetic and potential energy of the particles in the object]
what is chemical energy?
energy that can be transferred by chemical reactions
what is nuclear energy?
energy stored in the nucleus of an atom
what is magnetic energy?
the energy a magnetic object has when its near a magnet or magnetic field
what is electrostatic energy?
the energy a charged object has when its near another charged object
what ways can energy be transferred?
- heating
- waves
- electricity
- forces
how is energy transferred through heating?
it is transferred from one object to another that has a lower temperature
how is energy transferred through waves?
waves can transfer energy through radiation
how is energy transferred through electricity?
energy is transferred when an electric current flows
how is energy transferred through forces?
energy is transferred when a force moves or changes the shape of an object
what factors affect the rate of heat loss?
- the thicknessof the walls and roof
- the thermal conductivity of the walls and roof [the lower the thermal conductivity, the lower the rate of heat loss]
how can thermal conductivity be reduced?
by using thermal insulation; a material that has low thermal conductivity because the rate of energy transfer through an insulator is low
what does the energy transfer through a material depend on?
- the material's thermal conductivity
- thickness of material
- temperature difference of the two sides of the material
what is the equation for gravitational potential energy?
mass x gravitational field strength x height
what is the equation for kinetic energy?
0.5 x mass x speed^2
what is the equation for power?
energy transferred or work done / time
what is power?
how much work is done; amount of energy transferred per second
what is the equation for elastic potential energy?
0.5 x spring constant x extention^2
can energy be destroyed/created?
no, it cannot be destroyed or created; it can only be stored/transferred/dissipated [wasted]
is energy always transferred ussefully?
no, it is never entirely transferred usefully; some energy is always dissipated
where does all energy eventually end up going?
it eventually ends up being transferred to the thermal energy store of its surroundings
what is lubrication?
a way of reducing unwanted energy transfer due to friction
what is streamlining?
a way of reducing energy wasted due to air resistance or drag in water
what is the equation for efficiency?
useful output energy transfer/total input energy transfer
what is effiecency?
a measure of how much energy is transferred usefully
what is the specific heat capacity required practical?
Place a beaker on a balance and press 0
Add oil to the beaker and record the mass of oil
Place a thermometer and immersion heater in the oil
Read the starting temperature of the oil
Wrap the beaker in insulating foam to reduce thermal energy transfer to the surroundings
Connect a joulemeter to the immersion meter
Time for 30 minutes
Read the number of joules of energy that passed into the immersion heater
Read the final temperature of the oil
Calculate the specific heat capacity
what is specific heat capacity?
the amount of energy required to raise the temperature of 1kg of a substance by 1*c
what is the equation for specific heat capacity?
change in thermal energy / mass x temperature change
what are the main ways we use the earths resources?
- heating
- generating electricity
- transport
where does most of our energy come from?
fossil fuels:
- oil
- natural gas
- coal
what are non renewable energy resources?
energy resources that:
- will eventually run out
- are not replaced as fast as theyre used
what are the types of non renewable energy resources?
- coal
- oil
- natural gas
- nuclear fission
what is coal used for?
generating electricity
where is coal found?
extracted from underground
what are the advantages to using coal?
- enough available to meet current demands
- reliable; supply can be controlled to meet demands
- relatively cheap to extract and use
what are the disadvantages to using coal?
- will eventually run out
- releases carbon dioxide when burned [climate change]
- releases other gases such as sulfur dioxide
- oil spills into the oceans killing marine life
what is oil used for?
- generating electricity
- heating
- transport
where is oil found?
extracted from underground
what are the advantages to using oil
- enough available to meet currrent demands
- reliable; supply can be controlled to meet current demands
- relatively cheap to extract and use
what are the disadvantages to using oil?
- will eventually run out
-releases carbon dioxide when burned [climate change]
- releases other gases such as sulfur dioxide
- oil spills into the oceans killing marine life
what is natural gas used for?
- generating electricity
- heating
where is natural gas found?
extracted from underground
what are the advantages to using natursl gas?
- enough available to meet current demands
- reliable; supply can be controlled to meet current demands
- relatively cheap to extract and use
what are the disadvantages of using natural gas?
- will eventually run out
- releases carbon dioxide when burned [climate change]
- releases other gases such as sulfur dioxide