Using energy Flashcards
Name the different forms of energy.
Light Sound Kinetic Nuclear Electrical Gravitational potential Elastic potential Chemical potential
What does potential energy mean?
Potential energy is energy that can be stored/
What form of energy does any object above the ground have?
Gravitational potential energy
Detail the energy transfers when an object is falling.
A falling object transfers gravitational potential energy to kinetic energy.
What does the law of conservation of energy state?
Total amount of energy is always the same, it is not possible to create or destroy energy. It is only possible to transfer it from one form to another, or from one place to another.
It applies to all energy transfers.
Detail the energy transfers in a swinging pendulum.
A swinging pendulum transfers energy from gravitational potential energy to kinetic energy and back again as it swings.
Detail the energy transfers in a solar cell.
In a solar cell light energy is transferred to electrical energy.
Detail the energy transfers when an elastic band is stretched.
Stretching and elastic band transfers chemical energy to elastic potential energy.
What is a machine?
A machine is something that transfers energy from one place to another, or one form to another.
What is useful energy?
What is wasted energy?
Energy that is transferred to the place we want it in the form we want it.
Wasted energy is energy that is not usefully transferred.
Eventually, where is both useful and wasted energy transferred to and what effect will the energy have on this place?
What happens as the energy spreads out?
Both wasted and useful energy will eventually be transferred to the surrounding, and make them warm up.
It becomes more difficult to use it for further energy transfers.
In what way is energy usually wasted in a machine, and what effect does the energy have on the machine and its surroundings?
Energy is often wasted because of friction between moving parts of a machine, the energy warms the machine and the surroundings.
Give an example where friction is useful.
In the brakes of a car or bicycle.
How is some of the kinetic energy transferred when the brakes are applied to stop a vehicle?
Some of the kinetic energy is transferred to energy heating the brakes.
What unit is energy measured in?
Joules, J
