IV Energy Revision Flashcards
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
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 conducts energy. 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
Efficiency is always between?
0 and 1 (decimal) or 0 % and 100% (percentage)
State the 3 fossil fuels
Coal, oil and gas
State the order of start up times from shortest to fastest of the three fossil fuels
Gas, Oil, Coal (fastest to slowest)
Define a renewable energy resource
One that can be replenished and won’t run out
State the advantages of fossil fuels
Reliable (1) Short start up time of a few hours (1) cheap (1) can be used in many locations (1) doesn’t produce radioactive waste (1)
State the disadvantages of fossil fuels
Non renewable (1) Will run out (1) Produces carbon dioxide (1) which leads to global warming (1) Causes acid rain(1)
State the advantages of nuclear power
Reliable (1) A very concentrated source of energy (1) No carbon dioxide release (1) Doesn’t cause acid rain (1)
State the disadvantages of nuclear power
Slow start up time of a few days (1) Causes Radioactive waste (1) High decommissioning costs (1) Non renewable (1)
State the advantages of solar power.
Renewable (1) no fuel cost (1) no cardon dioxide (1) Doesn’t cause acid rain (1) can be used in remote locations (1)
State the disadvantages of solar power
Unreliable (1) Expensive to buy (1) Doesn?t produce much energy so need lots of solar cells (1)
State the advantages of wind
Renewable (1) Wont run out (1) no fuel cost (1) no cardon dioxide (1) Doesn’t cause acid rain (1)
State the disadvantages of wind
Unreliable (1) Visual pollution (1) Noise pollution (1) Don’t get much energy so needs a large area of wind turbines (1)
State the advantages of hydroelectric
Short start up time (1) Renewable (1) no fuel cost (1) no cardon dioxide emitted (1) Doesn’t cause acid rain (1)
