Physics Chapter 2 Flashcards
What do we measure energy in?
It is measured in kilojules but you can also measure in Jules.
Where does energy go?
Energy can not be destroyed but is transferred to things that you do to release energy.
Where is energy stored?
Different energy is stored in different categories like food, fuels, batteries are stored in the chemical store of your body.
How does a phone transfer energy?
If you use your phone you lose chemical energy and gain thermal energy.
What is the difference between energy and temperature?
If you compare a swimming pool with a beaker, even though they have the same temperature the swimming pool has a much more thermal source than the beaker of water.
What happen when you heat things up?
If you heat a solid up particles vibrate more; if you heat up a gas or liquid the particles move more faster and vibrate more.
What is radiation
Very hot things like coal give out waves we feel. This is radiation.
Is particles in radiation?
No, the sun gives radiation by travelling through space and space is a vacuum. Particles do not travel through vacuums.
What are microwaves measured in?
It is measure in Watts.
How to calculate power of appliances?
Energy
Power = —————
Time
How is objects cool down?
Heat is cooling down and particles start moving slowly and gradually stop to prevent energy from rising to keep it to room temperature.
How do you transfer energy by working?
You can transfer a bit of energy from working against gravity when you pick up books or work against friction when you slide books.
How to work out how much energy you have transferred by working?
Work done= force * distance
How to reduce energy?
You can use machines to do the job but release only a bit of energy. This can do the job quicker or better.
How does the gear in a bike work?
The gear increase the force you put in pedalling to move this saves energy of walking and is quicker. They are a bit like levers that rotate.
