Subjects
Subscribe
Search Skwirk
Year 9 NSW
»
Science
»
Force and motion
»
Energy
Topic : Energy
In this topic you will learn...
Chapter 1 :
Work and energy
Work is the application of a force over a distance
Work takes on many forms, such as moving or heating objects
Energy is the ability of an object to change the velocity, location, shape or state of another object
There are two main kinds of energy: kinetic energy and potential energy
Kinetic energy is found in objects that are in motion
Potential energy is energy that is stored in objects
Potential energy can be transformed into kinetic energy
Kinetic energy can be transformed into potential energy
Chapter 2 :
Kinetic energy
Kinetic energy is the energy of an object in motion
Kinetic energy can be expressed as KE =
mv
2
If something is moving quickly, it has lots of kinetic energy
If something is moving slowly, is has little kinetic energy
Kinetic energy can change the shape or velocity of another object
Chapter 3 :
Potential energy
Potential energy is energy that is stored in an object
Gravitational potential energy is energy stored by an object in a gravitational field
Elastic potential energy is energy stored by a compressed or extended elastic object
Electrical potential energy is energy stored by charged particles
Chemical potential energy is energy stored in the bonds within molecules
Nuclear potential energy is energy stored in the bonds within atoms
Chapter 4 :
Law of Conservation of Energy
The Law of Conservation of Energy states that energy cannot be created or destroyed
Energy can be transformed into kinetic energy, potential energy, heat, light or sound
A bouncing ball transforms energy between gravitational, kinetic and elastic energy
The bouncing ball loses energy through friction, changing it into heat and sound
A car loses energy through friction as it is transformed into heat and sound
Efficiency describes how much energy is lost through friction
Chapter 5 :
Power
Work is a measurement that describes a force and its efficiency to move an object but not the time taken
Power is the rate at which work is done
Power is work divided by time
A car has the same power as another car with half the mass that accelerates in half the time
Power is also equal to force times velocity
Topic Summary
Audio Summary
Play
|
Download
Text Summary
This topic includes
12 colour images
6 flash animations
1 final exam
ToolBox
Increase text size
Print this page
EMPTY?