1. Energy, Work & Power
ENERGY

2. Energy Defined as the ability to do work or to accomplish a task.
Can be stored and used later for work
Always conserved and cannot be created nor destroyed.
There are two categories of energy.

3. Potential Energy
Stored energy due to an object’s state. It is energy that has the potential to do work.
Types of potential energy:
Chemical: Energy stored within the molecules of a substance.
Nuclear: Energy stored within the nucleus of an atom.
Gravitational: The stored energy of an object due to its position height above a surface.

4. Elastic Potential: Energy stored by bending or compressing an elastic material (spring).
Electric Potential: Stored energy of charged objects due to their position and charge.
Magnetic Potential: Stored energy of magnetized objects.

5. Kinetic Energy The energy of motion. Types of Kinetic Energy:
Bulk Kinetic: Energy that is due to motion of an entire object (i.e a rolling cue ball).
Sound: Energy transmitted from molecule to molecule within a medium.

6. Thermal: Energy an object has due to motion of molecules within a substance.
Radiant: Energy that is transmitted via electromagnetic (EM) waves such as radio, light, x-rays, etc.
Electric: Energy associated with moving electric charges.

7. Energy Transformations
Energy can be transformed from one form to another. In the above lists.
Most household devices are ones that transform electrical energy to another form.
Consider a microwave oven:
Electrical energy -> Radiant Energy + Sound + Bulk Kinetic + Light

8. Eg.1: Determine the energy transformations in each case below.
Hand crank generator
Solar powered calculator
Battery powered flashlight

9. Eg.2: List as many devices that performs the following energy transformation around your house.
Chemical potential energy -> electrical energy -> light energy + sound energy
Electrical energy -> kinetic energy + sound energy