The six simple machines
name the six simple machines in their two categories
include at least 2 real life examples
include sub categories where necessary
draw a diagram where necessary to learn different parts
of each.
Simple machines give us a mechanical advantage (make
work easier) by making something easier to do but it
may take a little longer to do.
The Inclined Plane
Also known as a ramp. The load force is the vertical distance you need to move
an object and the effort force is what you put out when you move the object
along the slanted side. Examples are: wheel chair ramp, door stop...
ce
stan
rt di
effo
effo
rce
rt fo
load distance
load force = weight
The Screw
is simply an inclined plane wrapped around a post; it holds things together. The
length of the thread versus the length of the screw determines the
mechanical advantage of the screw. Example is a carpenter screw or a jar lid,
bolt, spiral staircase.
The Wedge
when two inclined planes meet at a point. It is used to travel through an
object. An example is a knife or an axe, bow of boat, snowplow...
The lever
There are 3 classes of levers. The classification depends on the
relative position of the fulcrum or pivot, effort and load.
Class 1 can move a load with little input force. The LOAD FORCE is
much bigger than the EFFORT FORCE. Examples are a teeter totter,
scissors and ???
Class 2 always moves a large load with a small effort force. Unlike a
class 1, the fulcrum is at one end. Examples are wheelbarrow,
nutcracker.
Class 3. Unusually, this type of lever makes it harder to move things
rather than easier, BUT it increases the distance that you can move
something. Examples are tennis racket, or a hockey stick.
Wheel and Axle
is a type of lever because it is a lever wrapped around a post. It moves
objects across a distance while reducing friction. The wheel turns the axle
which causes the movement. Example are a doorknob, a car or bicycle wheel.
The Pulley
is a variation on the wheel and axle. Instead of an axle, the wheel rotates a
rope or cord. As the wheel rotates, the rope moves in either direction. Now,
attach a hook to the cord, and you can use the wheel's rotation to raise and
lower objects. A flagpole is an example. There are two main kinds of pulleys:
fixed and moveable. When these two types are combined they are sometimes
known as a block and tackle.
Fixed
Moveable
block & tackle
Practice identifying simple machines in
the home.