Types of Energy

Potential Energy: A type of energy that is stored.  It is not actively being used but it can be converted to Kinetic energy when its being used.

• A car that is not moving but has a full tank of gas, a bouncy ball sitting on a table, food that has not been eaten

Kinetic Energy: A type of energy that will act upon an object to create work.  There are several types of energy that are all classified as kinetic energy.

• Light Energy
• Light, Sunshine
• Sound Energy
• Sound waves
• Chemical Energy
• Food as our body digests it, a battery
• Mechanical Energy
• Our bodies move while using Mechanical energy, any motion
• Heat Energy (sometimes this is listed separate from Kinetic energy but not everyone agrees with that)
• Toaster as it browns bread, light bulbs (some more than others)

Work & Power

We have been studying work and power.  Work is what happens when energy acts on an object.  For example, a toaster uses electrical energy and converts it to heat energy.  The work done by a toaster is toasting bread.  It is a change in an object due to energy.  The way work is calculated when an object is moving up is by multiplying the mass of an object by the rate of gravity (9.8 meters per second squared) by the height the object is being lifted.  We have used the example of climbing the stairs at Trillium.  The height of the stairs is 4 meters and if a student has a mass of 60 kg, the work could be calculated by
W = 60 x 9.8 x 4.  The unit for energy and work is Joules.

Power is the rate at which work is done.  It can be calculated by dividing Work by time (P=W/t).  This concept is one that is very similar to our concept of power used by most students in every day language.  The more powerful a student was going up the stairs it meant they either moved more mass at the same time or moved the same mass at a faster time.  Power's units are watts.