1. U3d-L4
January 22, 2008
DRILL
Identify which Core technology is represented by the examples below:
Door latch e. Crankshaft
Thermostat f. Cylinder
Fan g. Battery
Light bulb h. Gas tank
Mechanical
Electronic
Mechanical/Thermal
Optical
Mechanical
Structural
Electrical

2. U3d-L2
MACHINES
Machines are artifacts that transmit or change the application of power, force, or motion.
What is an artifact?
something created by humans usually for a practical purpose.
Machines can be simple or complex
Complex machines are comprised of….
Simple Machines

3. SIMPLE MACHINES Draw Sketches! LEVER INCLINED PLANE
U3d-L2
SIMPLE MACHINES
Principle: a law of nature underlying the working of an artificial device
Simple machines work on 2 basic principles:
Draw Sketches!
LEVER
INCLINED PLANE

4. PRINCIPLE OF THE LEVER LEVER Lever Wheel and Axle Pulley
U3d-L2
PRINCIPLE OF THE LEVER
LEVER
3 Categories of simple machines based on the principle of the LEVER:
Lever
Wheel and Axle
Pulley

5. PRINCIPLE OF THE LEVER 1st 2nd 3rd LEVER Lever Arm Fulcrum
U3d-L2
PRINCIPLE OF THE LEVER
LEVER
Lever Arm
Fulcrum
Applied Force
Load
3 different Classes of levers:
1st
2nd
3rd

6. PRINCIPLE OF THE LEVER LEVER Which is 1st class? 1st class:
U3d-L2
PRINCIPLE OF THE LEVER
LEVER
1st class:
The fulcrum is between the load and the effort force
Which is 1st class?

7. PRINCIPLE OF THE LEVER LEVER Which is 2nd class? 2nd class:
U3d-L2
PRINCIPLE OF THE LEVER
LEVER
2nd class:
The load is between the effort and the fulcrum
Which is 2nd class?

8. PRINCIPLE OF THE LEVER LEVER Which is 3rd class? 3rd class:
U3d-L2
PRINCIPLE OF THE LEVER
LEVER
3rd class:
The effort is placed between the load and the fulcrum
Which is 3rd class?

9. U3d-L2
LEVERS
Notice the direction of motion of the Force and Load for each of the 3 classes of lever.

10. 1st class 2nd class 3rd class
U3d-L2
HOMEWORK
Identify and sketch 3 common mechanical devices (not discussed in class during this lesson) that exhibit characteristics of the 3 classes of lever.
For example:
1st class
2nd class
3rd class