SP3 - Conservation of Energy Flashcards
What are the names of different energy stores?
Chemical energy
Kinetic energy
Thermal energy
Elastic potential energy
Gravitational potential energy
Nuclear energy
What are the names of different energy transfers?
Heat
Light
Sound
Kinetic
Electrical
Force
What are examples of items that store chemical energy?
Food
Fuel
Batteries
Where is kinetic energy stored?
Moving objects
Where is thermal energy stored?
Hot objects
Where is elastic potential energy stored?
Stretched materials
Squashed materials
Twisted materials
Where is gravitational potential energy stored?
Objects lifted above the ground
Where is nuclear energy stored?
Atoms
What does the law of conservation of energy state?
Energy cannot be created nor destroyed only transferred from one store to another.
What are the units for measuring energy?
Joules
What does a Sankey diagram show?
The amount of energy transferred to eachenergy transfer.
What is efficiency?
How good a machine is at transferring energy into useful forms.
What is the formula for efficiency?
Useful energy transferred
Efficiency = ————————————-
Total energy supplied
How do you reduce friction?
Lubrication
Why does the use of lubricant decrease make a machine more efficient?
Friction creates heat
The lubricant reduces the amount of friction, which therefore reduces the amount of heat energy wasted.
What does insulation do?
Slows down the rate at which energy is transferred out of the house.
What is conduction?
The process by which heat energy is transmitted through the material of a substance.
How does conduction work?
The particles in a solid heat up and start to vibrate quicker, the collisions cause the object it is touching to heat up to.
What is convection?
The process by which heat is transferred through the movement of liquids or gasses.
What is a convection current?
When hot air rises and cool air sinks, due to density.
The cool air that sinks heats up and rises, this repeats and forms a convection surrender.
What is radiation?
The process by which heat waves are emitted.
What surfaces absorb and emit infrared radiation easily?
Dark and dull surfaces.
What does it mean if an object has low thermal conductivity?
Energy is not transferred through them easily by heating.
What is the formula for gravitational potential energy?
Gravitational field strength =
mass x gravitational field strength x height
