1. Chapter 10
Simple Machine

2.  A machine is a device that helps us to overcome a load
with less effort or force.
 Devices that are classed as simple machines
are:
 The lever
 The pulley
 The wedge
 The screw
 The inclined and plane
 The wheel and axel

3.  A lever is an example of a simple machine
which turns about a fixed point called the
fulcrum (F) when a force, called the effort (E),
is applied to overcome a resisting force called
the load (L).
 Using a lever to overcome a large load with a
small effort.

4.  Thevarious devices that use the principle of
levers

5.  Load (L): the boulder to be lift
 Effort (E): the force used by the man to lift the
boulder
 Fulcrum (F): the point about which the stick
turns

6.  Fulcrum is between the effort and the
load
 Effort moves a longer distance but the
load moves a shorter distance
 Fulcrum near to the load

7.  Load is between the fulcrum and the effort
 Effort moves a longer distance but the load
moves a shorter distance

8.  Effort is between the fulcrum and the load
 Effort moves a shorter distance but the load
moves a longer distance

13.  When a force is applied to an object, it can
turn the object about a certain point called the
fulcrum or pivot. This turning effect of a force
is called the moment of a force.
 Moment of a force depends on:
 The force (F) applied
 The perpendicular distance (d) from the pivot
to the force (F).

16. The great pyramids of Egypt and the Great Wall of
China were built using simple tools such as levers,
rollers, wedges and inclined planes.

17.  Today we have invented, designed and built
complex machines
 Trains travelling at high speeds on land
 Ships and submarines travelling on the sea
and under the sea.
 Supersonic planes flying through the air
 Spaces exploring outer space and landing
astronauts on the moon.