1. Different Forms of Energy -Chapter 3

2. What is Energy? (404) Energy is the ability to do work.
The unit for energy is joules (J).
Law of Conservation of Energy:
Energy can not be created nor destroyed, it can only be transferred or transformed.

3. Machines or systems rarely convert energy 100% into something useful.
Energy Efficiency (404) p.72
Machines or systems rarely convert energy 100% into something useful.
To calculate the energy efficiency (in %) of a machine or system we use the formula:
Energy Efficiency =
Amt. of useful energy x 100
Amt. of Energy Consumed

4. The Law of Conservation of Energy (404)
Energy is always conserved, it is never "lost" or "wasted“.
Some energy transfers are useful and some are not.

5. Energy transfer

6. The battery transfers stored chemical energy as electrical energy
The battery transfers stored chemical energy as electrical energy. The electrical energy is transferred to the surroundings by the lamp as light energy and thermal energy (heat energy).

7. thermal and radiant energy
Energy Conversion
fan
electrical energy to
mechanical energy
coffee maker
electrical energy to
thermal energy
light bulb
electrical energy to
light energy to
thermal and radiant energy
Energy can be converted from one form to another or transferred from one object to another.
Law of conservation of energy — total amount of energy in the universe remains constant.
Energy cannot be created or destroyed.
In each step of an energy conversion some of the usable energy is "lost" or dissipated as heat, sound or light.
pencil sharpener
electrical energy to
mechanical energy
Timberlake, Chemistry 7th Edition, page 202