Technology Class

1. Energy Conversions &
Conservation
Forces, Motion, and Energy
p. 132-141

2. Conversions
• Changing one form of energy to another.
– Kinetic Energy-Thermal, Electrical, Sound, Light
– Potential Energy-Chemical, Nuclear
• Elastic Potential Energy-Rubber bands; any object that
will return to its original shape once it has undergone a
potential  kinetic conversion.

3. Some conversions of Electrical Energy
Electrical Energy Conversions
Hair Dryer Electrical  Thermal  Sound
Alarm Clock Electrical  Light  Sound
Battery Chemical  Electrical
Light Bulb Electrical  Light  Thermal
Blender Electrical  Kinetic  Sound

4. Types(s) of Energy:
Heat (thermal) energy in
flame
Light energy in flame
Chemical energy in match
used to light it

5. What is the energy transformation?
• A fire burning.
___________energy 
_________energy

6. What is the energy transformation?
• An apple
_________energy 
__________energy

7. What is the energy transformation?
• Nuclear Power Plant
__________energy 
___________ energy 
__________ energy

8. What is the energy transformation?
• Desk Lamp
____________ energy 
______________ energy

9. What is the energy transformation?
• Kerosene lantern
___________ energy 
__________ energy 
___________ energy

10. Machines-Mechanical Energy
• There are simple • There are complex
machines such as: machines such as:
– Screws – Scissors-2 wedges and
– Levers-Claw end of a a lever
hammer, see saw – Wheelbarrows-lever
– Wheel & axle-large and wheel & axle
wheel secured to a
smaller shaft
Complex machines are
– Pulley-flagpole formed from 2 or more
– Inclined plane-ramp simple machines.

11. Conservation
• Law of conservation of energy
• Friction
• http://youtu.be/GTVqtGTfIc8

12. Closed System
• Energy is conserved within a closed system
where a group of objects only transfers energy
to each other.

13. Energy Efficiency
• A comparison of the amount of energy before
a conversion with the amount of energy after
a conversion.
– Remember, every time energy converts it loses
friction.