Energy and Work Flashcards
Recall and apply law of conservation of energy
Energy can’t be destroyed or created but may be transformed from one type to another
Why are energy transformations not 100% efficient
Some energy may be transferred into the surrounding environment as unwanted heat, sound or light
Energy transformations in everyday life
A hairdryer uses 1200Joules. 600Joules for drying hair. Wasted sound energy.
Examples of conversion of electrical energy in light
Electrical energy turns into light to illuminate rooms
Examples of conversion of electrical energy in movement
Electrical energy to make fan blades spin for breeze
Examples of conversion of electrical energy in sound
Electrical energy creates sound waves for music or voice
What is energy
Energy is the ability to do work
How to calculate work done
You calculate work done by Force x distance (W=Fd)
Gravitational potential energy
The energy an object has due to its position above earth due to its height
Electrical potential energy
The energy that is needed to move a charge against an electric field
Chemical potential energy
The energy stored in the chemical bonds of substance
Elastic potential energy
Energy stored as a result of applying a force to deform an elastic object
Kinetic energy
Energy possessed by objects that are moving
Thermal energy
Energy that causes objects to gain temperature
Light energy
Energy that may be release, for example, when an object is hot or by a nuclear reaction by a star
Sound energy
Energy that is carried by the air in a room and detected by the ear
Nuclear potential energy
Energy stored in nucleus of atoms that can release energy slowly like in a reactor or quickly like a nuclear explosion.
Renewable energy
They can be easily renewed at the rate it is used
Non Renewable energy
Cannot be regenerated
Renewable energy examples
Geothermal, solar, hydroelectric
non Renewable energy examples
Coal, oil, uranium
When is work done
When the point of a force is applied and it moves in the direction of the force.
How to calculate the work done
Multiplying the force and distance it moves (W=Fd)
The unit for work and energy
Joule
How can work be done to increase Kinetic energy
Pushing or pulling to speed up the object
How can work be done to increase GPE
Lifting the object upward
How can work be done to increase EPE
Stretching or compressing and elastic object like a spring
