The document discusses simple machines including their definitions, types, and calculations of mechanical advantage and efficiency. It describes three main types of simple machines: inclined planes, wedges, and screws. It also covers the three classes of levers and provides examples for each. Ideal mechanical advantage calculations are provided for each machine.

1. Simple Machines

2. Objectives
 Explain how machines make work
easier
 Calculate Mechanical Advantage of a
machine
 Calculate Efficiency of a machine

3. Key Words
 Simple Screw
Machines
Lever
 Inclined Plane
Fulcrum
 Wedge

4. What is a Simple Machine?
A simple machine
has few or no
moving parts.
 Simple machines
make work easier

5. 3 types of simple machines
 The inclined plane
 The Wedge
 The Screw

6. What is an inclined plane?
A sloped surface
 An inclined plane allows you to exert
your input force over a longer distance
 Ideal Mechanical Advantage =

7. Inclined Planes
 An inclined plane is
a flat surface that is
higher on one end
 Inclined planes
make the work of
moving things easier

9. Increase Force Increase distance
 When the output  When the output
force is greater force is less than
than the input force the input force the
the mechanical mechanical
advantage is advantage is less
greater than 1. than 1.
• If only the direction changes, both the input force
and output force will be the same

11. What is efficiency?
 Output Work / Input work x 100%

12. EFFICIENCY
 Theefficiency of a machine compares
output work to input work
Output Work
100
Input Work

14. Inclined Planes
How do Inclined Planes work?

15. Wedges
Can your teeth be machines?

16. Wedges
 Two inclined planes joined
back to back.
 Wedges are used to split
things.

17. Ideal Mechanical Advantage
Inclined Plane Wedge
 Divide the length  Length of the plane
of the incline by divided by its width
the height  Longer and thinner
the wedge is,
greater the
mechanical
advantage

18. Screws
A screw is an
inclined plane
wrapped around a
shaft or cylinder.
 The inclined plane
allows the screw to
move itself when
rotated.

20. Mechanical Advantage of
Screw
 length of thread around the
screw by the height of the screw

21. LEVERS

22. Objectives
 How are levers
classified

23. What is a Lever?
A lever is a rigid bar that is free
to pivot, or rotate on a fixed
point
The fixed point that the lever
pivots around is called the
fulcrum

24. Levers-First Class
 In a first class lever
the fulcrum is in the
middle and the load
and effort is on
either side
 Think of a see-saw

25. Levers-Second Class
 In a second class
lever the fulcrum
is at the end, with
the load in the
middle
 Think of a
wheelbarrow

26. Levers-Third Class
 In a third class lever
the fulcrum is again
at the end, but the
effort is in the
middle
 Think of a pair of
tweezers

29. Ideal Mechanical Advantage
 IdealMechanical Advantage =
Distance from fulcrum to the input
force
Distance from fulcrum to the output
force

32. Putting Machines Together

33. Key Words
 Pulley
 Wheeland Axle
 Compound Machine

37. Ideal Mechanical Advantage
 Ideal Mechanical Advantage =
Radius of Wheel
Radius of Axle

39. Compound Machines
 Howdo Compound Machines
work?
 Withina compound Machine, the
output force of one simple machine
becomes the input force another
simple machine

40. Wheels and Axles
 The wheel and axle
are a simple
machine
 The axle is a rod
that goes through
the wheel which
allows the wheel to
turn
 Gears are a form of
wheels and axles

41. Pulleys
A Pulley is a simple
machine made of a
grooved wheel with a
rope or cable wrapped
around it.
 (A pulley needs a rope,
chain or belt around the
groove to make it do
work)

42. Simple Machines
 Simple Machines
can be put together
in different ways to
make complex
machinery

43. Give examples for each class
of lever
 Hwpage:
99-101