Chapter 2: Energy Flashcards
(27 cards)
What is the law of conservation of energy?
Energy cannot be created or destroyed only transferred
What are three different ways of transferring energy between different stores?
Light, sound and electricity
What measures temperature?
A thermometer in degrees celsius (ºC)
What does temperature measure?
The average energy
What does thermal energy measure?
The total energy
What happens to the particles when we heat them?
They gain more kinetic energy, and vibrate more or faster
True or False. The energy needed to heat an object depends on the mass, material and temperature rise.
True
What is equilibrium?
When objects have the same thermal energy
What is a renewable energy source? Give two examples
A renewable energy source is one that will not run out. E.g, wind, tidal, solar, hydroelectric
What is conduction?
When particles collide into others when they vibrate, only occurs in solids
What is convection?
A part in contact with the heat source gets hotter. The particles move faster, causing them to become further apart, and a decrease in density. The hot part then rises, and cooler, denser parts fall and take its place at the bottom. They now heat, so the cycle continues
What is a non-renewable energy source? Give two examples
A non-renewable energy source is one that will eventually run out, they cannot be reused and are formed from fossilised remains from millions of years ago
What is the first step of power being generated?
Fossil fuels are burned to heat water, which produces steam.
What is the second step of power being generated?
The steam turns a turbine, which spins a generator
What is the third step of power being generated?
The current created is sent to our offices, factories, and homes down long cables.
What do fossil fuels do?
They produce greenhouse gases, such as carbon dioxide
What is power?
The rate of energy transfer- how much energy is transferred each second
What are energy bills measured in?
1 kilowatt per hour
How could you reduce energy bills?
Use fewer appliances or more efficient ones
What is the formula for work done?
Work done (J) = force (N) x distance (m)
What simple machines can make work easier?
Levers and gears
How does infrared radiation transfer energy?
Without particles- it is a wave
True or False. All objects emit radiation?
True
What does the amount of radiation depend on?
Their temperature and the surface (colour and rough/smooth)
