1. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Simple and Compound Machines

2. What are Simple Machines?
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
What are Simple Machines?
A device that allows work to be performed with less effort
A device with few or no moving parts
A device that makes work easier by changing force, distance, or by changing the direction of the force
What are Compound Machines?
Two or more simple machines working together to make the work easier

3. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
The 6 Simple Machines

4. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Lever
A rigid bar used to exert a pressure or sustain a weight by pivoting on its fulcrum

5. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Parts of a Lever
If the fulcrum is located at the midpoint of the lever arm and the effort is equal to the load, then the lever will be perfectly balanced.
Lever Arm
Effort
Load
Fulcrum

6. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Types of Levers
You can identify the different types of levers by the middle component.
Can you identify each type of lever on the next slide?

7. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Levers
First Class = See-saw, scissors, fingernail clipper arm
Second Class = wheelbarrow, nut cracker
Third Class = fingernail clipper clipping mechanism, tweezers

8. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Wheel & Axle
A wheel is a lever arm that is fixed to a shaft, which is called an axle.
The wheel and axle move together as a simple lever to lift or to move an item by rolling.

9. Examples of Wheel & Axles
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Wheel & Axles

10. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Pulleys
A grooved wheel around which a rope, belt, or chain passes
Used to change the direction or magnitude of a force

11. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Pulleys

12. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Pulley Systems
Fixed Pulley – Does not rise or fall with the load that is being moved
Movable Pulley – Rises and falls with the load that is being moved
Block and Tackle – Two or more pulleys used in combination

13. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Inclined Plane
Flat surface set at an angle or incline
Most common inclined plane is a ramp
Able to lift objects by pushing or pulling the load

14. Examples of Inclined Planes
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Inclined Planes

15. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Wedge
Functions as a moving inclined plane
Tapers to a thin edge and is used for splitting or for tightening by being driven into something

16. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Wedges
Almost all cutting tools make use of the wedge.

17. Simple and Compound Machines
Screw
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
An inclined plane wrapped around a cylinder, forming the path and pitch
Pitch is the distance between two threads
A screw is used as a threaded fastener. It changes rotary motion to linear force.

18. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Examples of Screws

19. What Kind of Simple Machine Is This?
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
What Kind of Simple Machine Is This?
Wedge
Pulley
Wheel and Axle
Screw
Inclined Plane
Lever

20. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Compound Machines
Compound machines consist of two or more simple machines put together.
Most devices are compound machines.
They can do more difficult jobs because their mechanical advantage is greater.
What two simple machines are in scissors?
First Class Lever and Wedge

21. Name the Simple Machines Present in Each Compound Machine
Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Name the Simple Machines Present in Each Compound Machine
Bicycle – lever (brake handles), wheel and axle (wheels and pedals), screw (seat adjustment)
Shovel – lever, wedge
Wheel barrow – 2nd class lever, wheel and axle
Jack stand – wheel and axle, screw
Pencil sharpener – wheel & axle, wedge

22. Simple and Compound Machines
Gateway To Technology
Unit 5 – Lesson 5.3 – Applied Physics
Image Resources
Microsoft, Inc. (2009). Clip Art. Retrieved January 22, 2009, from