1. Simple Machines

2. Nature of Machines
Machines are any device that transfer a force from one place to another.
Nutcracker, ramp, engine
All complicated machines contain many small simple machines.
Simple Machines – the basic devices for transferring mechanical forces in all machinery.

3. Action of Machines Effort Force – the force you apply to the machine.
Effort Distance – The distance the effort force acts through.
Resistance Force – The force the machine applies to some objects.
Opposite the effort force.
Resistance Distance – The distance through which the resistance force acts.

4. Resistance Distance
Effort Force
Effort Distance
Resistance Force
Fulcrum

5. Laws of Machines
Under ideal conditions, the amount of work put into a machine is equal to the amount of work the machine does.
Ideal conditions refer to NO HEAT, produced by friction, and NO AIR RESISTANCE, created when the machine is used.
Real machines do create friction and therefore creates less energy than it takes in.

6. Purpose of Machines Machines make work seem easier and faster.
Multiply a force
Change the direction of a force
Multiply a distance
Multiply speed

7. Types of Simple Machines
There are six types of simple machines
Compound machines are made from one or more of these six simple machines.
Lever – a bar that rotates around a fixed point, fulcrum.
Fulcrum

8. 3 Classes of Levers First Class Lever Second Class Lever
Fulcrum is between the input force/Effort and the load.
Ex. Claw end of a hammer
Second Class Lever
Load is between the fulcrum and the input force/effort
Ex. A can opener
Third Class Lever
Input force/effort is between the fulcrum and the load.
Ex. Your arm lifting a weight

9. Types of Levers
Label the Effort (E), Resistance (R), and Fulcrum (F) in each of the pictures and then determine the type of lever each represents.
1st Class E
2nd Class R F E F R R
2nd Class
3rd Class F E F E R

10. E
2nd Class
1st Class R E F R F
1st Class
3rd Class F F E R E R

11. Types of Simple Machines
Inclined Plane – A flat surface that slants up at an angle.
Ex. A ramp

12. Types of Simple Machines
Wedge – two inclined planes placed back to back.
The longer and thinner the wedge is, the less energy is required to do work.
Ex. Knife, ax, razor blade.

13. Types of Simple Machines
Screw – an inclined plane that is wrapped around a cylinder
Rotates with each turn moving it up or down
The closer the threads, or ridges, the easier the work is.
Ex. A jar lid, soda bottle cap, bolts

14. Types of Simple Machines
Pulley – A grooved wheel that holds a rope or cable.
It can change either the direction or the amount of an effort force.
2 Types:
Fixed
Movable

15. 1. Fixed – attached to a stationary object.
2. Movable – not attached to a stationary object

16. Types of Simple Machines
Wheel and Axle – two circular object of different sizes rotating in a circle.
Two different sized wheels:
Axle – the smaller wheel
Wheel – turns about the smaller axle.

17. Identify the Simple Machine
Lever
Wedge
Pulley
Screw
Wheel and Axle
Inclined Plane

18. Identify the Simple Machine
Wheel
and
Axle
Wedge
Pulley
Lever
Lever
Wheel and
Axle
Lever
Inclined Plane
Screw