Energy - Paper 1 Flashcards
To revise the energy topic (paper 1)
What is a system?
an object or group of objects
Describe the energy changes when a ball is thrown upwards
Kinetic energy into GPE and thermal
Describe the energy changes when an object hits an obstacle
Kinetic into Thermal and sound
Describe the energy changes in a torch
Chemical into electrical into thermal and light
State the equation and all units for kinetic energy
kinetic energy (J) = 0.5 × mass (kg) × speed2 (m/s)
E = 0.5 x m x v2
State the equation and all units for GPE
GPE (J) = mass (kg) × gravitational field strength(N/kg) × height (m)
GPE = mgh
Define specific heat capacity
the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.
State the units for specific heat capacity
J/kg °C
Define Power
Rate at which energy is transferred into a new form
State the equation with all units for Power.
Power (W) = energy (J)/ time (s)
P = E/t
Define 1 W
An energy transfer of 1 joule per second
State the conservation of energy
Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed.
Define thermal conductivity
How well a material can insulate. The higher the thermal conductivity of a material the higher the rate of energy transfer by conduction across the material.
What does a larger thermal conductivity mean?
cvsvs
How can heat loss from a building be minimised?
Using thicker walls and materials with a lower thermal conductivity
Define efficiency
How effective a device is at converting its input energy into a useful output form of energy
State the equation for efficiency
efficiency = useful output energy / total input energy
State the 3 fossil fuels
Coal, oil and gas
Define a renewable energy resource
One that can be replenished and won’t run out
State the advantages of fossil fuels
- Reliable
- Short start up time of a few hours
- cheap can be used in many locations
- doesn’t produce radioactive waste
State the disadvantages of fossil fuels
- Non renewable
- Will run out
- Produces carbon dioxide which leads to global warming
- Causes acid rain
State the advantages of nuclear power
- Reliable
- A very concentrated source of energy
- No carbon dioxide release
- Doesn’t cause acid rain
State the disadvantages of nuclear power
- Slow start up time of a few days
- Causes Radioactive waste
- High decommissioning costs
- Non renewable
State the advantages of solar power.
- Renewable
- Wont run out
- no fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
State the disadvantages of solar power
- Unreliable
- Expensive to buy
- Don’t get much energy so need lots of solar cells
State the advantages of wind
- Renewable
- Wont run out
- no fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
State the disadvantages of wind
- Unreliable
- Visual pollution
- Noise pollution
- Don’t get much energy so need a large area of wind turbines
State the advantages of hydroelectric
- Short start up time
- Renewable
- Wont run out
- no fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
Disadvantages of hydroelectric
- Expensive to build the dam
- Flooding of surrounding areas
- Damage to animal habitats
Advantages of geothermal
- Short start up time
- Renewable
- Wont run out
- Low fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
Disadvantages of geothermal
- Expensive to drill
- Only suitable in certain locations
Advantages of wave power
- Renewable
- Wont run out
- No fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
Disadvantages of wave power
- Unreliable
- Difficult to maintain and repair
- Restricts shipping lanes
Advantages of tidal
- Reliable - as tides can be predicted
- Renewable
- Wont run out
- Low fuel cost
- no cardon dioxide
- Doesn’t cause acid rain
Disadvantages of tidal
- Difficult to maintain and repair
- Restricts shipping lanes
Advantages of Biomass
- Reliable
- Renewable
- Carbon neutral
Disadvantages of Biomass
- Release carbon dioxide
- Takes up land which can be used for crops
What are the nine types of energy?
- Kinetic
- sound
- light
- thermal
- electrical
- gravitational potential
- elastic potential (strain)
- chemical
- nuclear
What is ‘wasted energy’?
Energy that is transformed to either the wrong place or the wrong form. This is normally thermal or sound which spreads out to the surrounding .
What is ‘useful energy’?
The energy transformed to where it is wanted in the form wanted
If energy can not be created or destroyed why are we concerned with waster energy?
A lot of energy is wasted as thermal which dissipated and spreads out to the surroundings. This energy becomes so spread out it can’t be reused usefully again.
What is the equation for work done? Include all units
Work done (J) = force (N) x distance in direction of force (m)
W = F x d
What is the relationship between work done and energy transferred
Work done = energy transferred
For a falling object why would the increase in kinetic energy not equal the decrease in GPE?
Air resistance/friction would cause some energy to be lost as thermal which would be dissipated to the surroundings
Why do falling objects reach different speeds?
Different objects have different surface areas, this means a different amount of thermal energy will be lost due to air resistance.
Or difference mass will have different terminal velocities
