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) × speed Squared (m/s)
State the equation and all units for GPE
g.p.e. (J) = mass (kg) × gravitational field strength(N/kg) × height (m)
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)
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.
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 so they take up a lot of space
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 buy 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 Low 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
Take 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
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?
Work done = force x distance in direction of force
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
