All about simple machines here!!!
There are ways of making work easier
on you. Let's look at simple machines.
referred to as a
'ramp' the inclined
plane allows you to
multiply your force
over a longer
distance. You do the same amount
In other words, you of work, it just seems easier
exert less force but because you spread it over
for a longer time.
The Wedge: A
wedge works in a
similar way to the
inclined plane, only
it is forced into an
object to prevent it
from moving or to
split it into pieces. A
knife is a common
use of the wedge.
The Screw: The
screw is really just
an inclined plane
wrapped around a
rod. It too can be
used to move a load
(like a corkscrew) or
to 'split' an object
(like a carpenter's
The Lever: The lever is simply a bar supported at
a single point called the fulcrum. The positioning of
the fulcrum changes the mechanical advantage of
the lever. Look at how you can manipulate the
position of the fulcrum relative to the heavier
weight to lift the 200g mass with only 100g of
Wheel and Axle
The Wheel and Axle:
Any large disk (the wheel)
attached to a small
diameter shaft or rod (the
axle) can give you
Turning a screw with a
screwdriver is a simple
Can u think of
example of a wheel and
others we use
First Class Lever
The first class lever is the one you may
be most familiar with. It uses a fulcrum
in between, and the applied force and
load are at opposite ends.
The diagram above shows a first class lever set up to
move a heavy load with a small applied force. The force
must be applied over a long distance, in order to make
the heavy load move just a small amount.
By adjusting how far the fulcrum is from the
load, you can control the mechanical
advantage. The closer it is to the load, the
more force is applied.
Second Class Lever
The second class lever is one where the
fulcrum is at one end, and the applied force
at the other. The load that is to be moved is
This lever is different in how it works ... it
causes the load to move in the same
direction as the force you apply.
Just as with a first class lever, how close
the load is to the fulcrum determines by
how much your force will be multiplied.
If you want to move a very large load
with a small applied force, you must put
the load very close to the fulcrum.
Third Class Lever
The third class lever is the strangest ... and the one
you use the most!
The fulcrum is once again at one end of the lever, but
this time the load is at the other end, and you apply
a force in between.
This lever can not give any mechanical advantage.
Regardless of where you apply the force, the force
you apply must always be greater than the force of a
If you were using this lever to lift an object at a
distance, it would require less force to just
stand above it and lift it up ... using the lever
will require more force!
So why use a third class lever at all?
The answer lies in the fact that the load moves in the
same direction as the force you apply, which is
convenient. So is the application of force between
the load and the fulcrum