Transcript Types of Simple Machines : - Year 6 and 7 Mathematics

- Megastructures don’t build themselves.
- From the ancient Egyptians to modern
day Emirati, machines have always been
used to create our mega masterpieces.
- What mechanics were used in ancient
times?
- What mechanics are used today?
Engineers use scientific knowledge to design
and build machines that make our lives easier,
bridges that carry heavy loads, and buildings
that don’t fall over.
These tasks involve using forces.
A machine is a device that makes a physical
task easier (eg. cars, bikes, cranes, lifts and
escalators) to do.
SIMPLE MACHINES: is a machine with few
or no moving parts to which you apply just
one force (wheelbarrow, .
Types of Simple Machines:
1. Lever
2. Pulley
3. Wedge
4. Wheel and axle
5. Screw
6. Inclined plane
- Can-openers, scissors, tongs, spanners,
hammers, brooms, tennis racquets and staplers
are examples of levers.
- A lever is a simple machine that uses the
turning effect of a force. It is a bar that pivots
on a fixed point. Eg hockey stick, seesaw,
prybar)
- The turning (fixed) point of a lever is called a
fulcrum.
- The resistance to motion that a lever works
against is called the load.
- The force used to cause movement is called an
effort.
-Many of the bones in your own body are levers.
- The long bones in your arms and legs are the
most obvious examples of levers.
- Joints such as your elbow or knee act as
fulcrums.
-Your muscles pull on parts of the bone to create
the effort.
- The load is the resistance to motion that your
bone works against (eg. a basketball, a bucket of
water or a heavy weight at the gym).
-When you bend your arm to lift a weight,
the effort is provided by your biceps
muscle where it joins a bone called the
radius in your forearm, just below the
elbow.
-Your elbow is the fulcrum.
- The weight you are lifting is the load.
- The effort is your forearm and biceps.
-Find three levers in your
home.
- Draw these, and label:
 The fulcrum
 The load
 The effort