Using Energy Flashcards
What are the three forms of stored energy
- chemical potential
- gravitational potential
- elastic potential
Name the different forms of energy
- kinetic
- nuclear
- light
- sound
- electrical
- chemical potential
- elastic potential
- gravitational potential
What sort of energy does a compressed spring have
Elastic potential
What type of energy does every object that can rise off the ground have
Gravitational potential
What are the energy transfers in a falling object
Gravitational potential; kinetic
What is the conservation of energy
Energy cannot be created or destroyed
What energy transfers take place when you turn on a torch
Chemical; electrical; light and heat
What are the energy changes in an elastic band
Chemical energy; elastic potential energy
What are the energy transformations in a solar cell
Light; electrical
In terms of energy what happen when you burn fuel
Chemical energy in the fuel is transferred to the surroundings, which gets warmer
What are the energy transfers in a swinging pendulum
Gravitational potential; kinetic; gravitational potential; kinetic…ECT
What is a machine, in terms of energy
Something that transfers energy from one place to another or from one form to another
What are the two kinds of energy do you get out of a machine
- useful
- waste
What is useful energy
Energy that is transferred to the place we want or in the form we want
What is waste energy
Energy that is not usefully transferred
What happens to the wasted energy of an appliance
They are transferred to the surrounding which get warmer
How is energy often wasted between the moving parts of a machine
Friction
What are the effects in terms of energy of friction in a machine
It heats up the machine and the surroundings
In which machines is friction useful
Car brakes and bike brakes
Why Do we say energy is wasted not lost
Because the law of conservation states that energy cannot be created or destroyed
What is the unit for energy
Joules
What is the energy supplied to a machine often called
Input energy
If 100 joules is input into a machine but 20 joules is wasted as sound energy, how much energy is useful
80 joules
What makes a machine more efficient
If it wastes less energy
Is there any machine that is 100% efficient
Yes an electric heater because it transfers all of its electrical heat to its surroundings
When is electrical energy transferred
When an electric current flows
Why do electrical appliances, such as TVs and computers have vents
So the wasted energy is transferred to the surroundings making them warmer, rather than the device itself .
