Energy And Energy Transfers Flashcards
What is the law of conservation of energy?
Energy can neither be created nor destroyed-only transferred (from one type to another)
What is energy measured in?
In joules (J). One joule i a very small amount of energy, so we often use kilojoules (KJ). 1 kilojoule = 1000 J
Name three examples of fuels?
Food like chocolate, coal and wood
What do fuels need so that they can be burned and used?
Oxygen
What type of store does food, fuels and batteries get stored in?
Chemical store
What type of store does hot objects get stored in?
Thermal energy
What type of store does moving objects get stored in?
Kinetic energy
Energy to do with position in a gravitational field is stored in a…
Gravitational potential store
What type of store does changing shape, stretching or squashing get stored in?
Elastic store
Is the total energy before an action the same as afterwards?
Yes
State three ways that energy is transferred between stores?
Electric current, light, and sound are ways of transferring energy between stores
What does it mean if energy has been dissipated?
For example energy is transferred to the thermal store of the surroundings rather than the store that you want it to go to
What is temperature?
the degree or intensity of heat present in a substance or object, especially as expressed according to a comparative scale and shown by a thermometer or perceived by touch.
What do you measure temperature in?
We measure temperature in degrees Celsius (°C)
What is a thermometer?
You use a thermometer to measure temperature. Some thermometers have a liquid inside a very thin glass tube that expands when it is heated. Other thermometers are digital
What happens when you heat things up?
Heating changes the movement of particles. If you heat a solid the particles vibrate more. If you heat a liquid or a gas the particles move faster and vibrate more.
What does the energy that you need to increase the temperature of a material depend on?
- The mass of material
- What the material is made of
- The temperature rise that you want
What is meant by equilibrium?
Equilibrium means when two of the same forces, such as temperature, have the same or equal energy.
What is a conductor?
A material that allows the flow of electricity or heat. A metal is a good conductor of energy.
What is conduction?
When something like energy is transferred through something very quickly.
How can energy be transferred?
Energy can be transferred by conduction, convection, or radiation
In conduction how do particles transfer energy?
By colliding with other particles when they vibrate
What is an insulator?
Energy is not transferred very easily through materials like wood. Wood and many non-metals are poor conductors. They are insulators. This doesn’t mean they don’t conduct at all but energy is transferred very slowly through them.
What is the best at insulating, solids, liquids or gases?
Solids are best at insulating, then liquids and finally gases