2. Agenda Simple Machine Lever Screw Wheel- and- Axle Inclined
plane Pulley Wedge Application of simple machines in a complex
machine
3. What are Simple Machines? machines with few or no moving
parts. make work easier. use energy to work. change the direction
of a force such a push or pull.
4. Types of Simple MachinesThere are 6 simple machines. They
are:1. Lever2. Screw3. Wheel- and- Axle4. Inclined Plane5. Pulley6.
Wedge
5. LeverA lever is a straight rod that rotates around the
fulcrum. There are 3classes of levers representing variations in
the relative locations of thefulcrum, the load and the effort.
Class-1Here fulcrum is located between the effort & the
load.Examples of class-1 lever: Pliers, See-saw
6. Class-2Here Load is located between the effort and the
fulcrum.An example of class-2 lever :Wheelbarrow
7. Class-3Here Effort is located between the Load & the
Fulcrum.Examples of Class-3 lever: Human Arm lifting a Load,
Tweezers
8. Screw A screw is a thin rod with edges ,or threads that
curve around it. Turning a screw produces a force that can push the
screw into wood or tighten it against a nut. They are also used on
jars and other containers so that lids close tightly. Types of
screw Lag bolt: A lag bolt is actually a screw that is very large
andonly partly threaded. The head is square and needs tobe turned
with a wrench rather than a screwdriver.The lag bolt is used when a
standard wood screw simplyisnt strong enough. It will probably be
the largestscrew youll find in your local hardware store .
9. Wood Screws: The standard wood screw is used to secure one
piece of wood to another. Screws with a rounded head are generally
preferred for thinner pieces of wood. Screws with a flat or
oval-shaped head are a better choice when you will be counter
sinking the screw for a more decorative appearance. Brass Screws:
Brass screws are essentially just wood screws that are made from
brass instead of steel. They are preferable in some cases because
they dont rust. Brass screws also add an aesthetic appeal that may
be lost when using steel screws.
10. Security Screw:Security screws feature specially shaped
heads that allow them to beinserted with a flat-blade screw driver.
This special shape features aslot designed in such a way that the
screwdriver can grip it only whenturning the screw clockwise. The
security part of this screw is in thefact that since the
screwdriver cannot grip it for turning counterclockwise, the screw
cannot be removed.
11. Wheel- and- AxleWheel and axle work together to make a
simple machine. It is a wheel thatturns around a rod, called an
axle that is fixed to the center of a wheel. Awheel and axle can
help move things faster or more easily, and also helpthings turn.
Heavy things can be difficult to push across a surface and
canrequire a lot of force. But, if you add wheels to the bottom, it
becomesmuch easier. When the axle is turned, the wheel moves a
greater distancethan the axle, but less force is needed to move
it.Examples: A steering wheel in a car, Ferris wheels, doorknob,
skateboard.
12. Inclined PlaneAn inclined plane is a flat surface that is
raised at one end. It takesless force to move an object up along an
inclined plane than it does tolift it straight up.Examples : Ramps,
sloping roads
13. PulleyA pulley is a simple machine that has a rope or cable
that goes over an wheel.A pulley helps people lift things up with
much smaller forces. By pulling downon one end of the rope, a
person can lift an object attached to the other end.The length of
the string used to lift the pulley determines how much force
isneeded.Examples : Flag poles, crane, blinds , elevator,
fishingrod
14. Types of pulleys Fixed: A fixed pulley is fastened to one
spot, and does not move around. It provides no gain in force,
distance or speed, but it changes the direction of the force which
means the force is equal on both sides of the pulley and there is
no multiplication of force. Examples of fixed pulleys can be seen
on flag poles, drapes, or on a sail mast. Movable: A movable pulley
moves along a rope or wire. It provides a gain in force. A movable
pulley is used to multiply forces. If one end of the rope is
anchored, pulling on the other end of the rope will apply a doubled
force to the object attached to the pulley. Compound: A compound
pulley, also called a block and tackle, is a combination of a fixed
and a movable pulley that means several pulleys are mounted on each
axle. This type of pulley changes direction, and yields a gain in
force at the same time.
15. WedgeA wedge is a piece of material that narrows to a thin
edge. Wedges areused to split things. The purpose or advantage of
the wedge is to changethe direction of the applied force. Pushing
the wedge in one directioncreates a force in sideways
direction.Example : Axe, knife , chisel, doorstop, saw, hammer,
bulldozer, zipper,scissors, fork, bow of a boat or ship
16. Complex machinesSimple machines can be combined to create
complex machines.Complex machines can be as small as a mechanical
watch or as largeas a construction crane. Complex machines are also
called compoundmachines. Two or more simple machines work together
to form acomplex machine. Compound machines can do more difficult
jobsthan simple machines alone.Examples of complex machines
are:Bicycle, wheel barrow, garden hoe , stapler, car jack ,crane ,
towtruck, bicycle, can opener, lawn mower
17. Simple machines used in complex machines : Compound Machine
Simple Machine Wheel and axle Lever Wheel barrow Wedge Lever Garden
hoe / Stapler Wedge Screw Car Jack Lever Pulley Crane / Tow
truck
18. Compound Machine Simple Machine Wheel and axle Pulley Lever
Screw Bicycle Wheel and axle Wedge Lever Can opener Wheel and axle
Screw Lever Wedge Lawn Mower
19. A wheelbarrows long handles act as levers, and it rolls on
a wheelwhich acts as wheel and axle.A Garden hoe is made up of a
lever and a wedge. The handle of thehoe is a lever, while the blade
that cuts into the ground is a wedge.A Stapler is made up of two
Simple Machines, Wedge and Lever. Thestaples in a stapler are
wedges because they pierce through papers.The top arm of the
stapler is a Lever, it has a fulcrum or a pivot point,which allows
the top of the stapler to move up and down. When you putenergy on
this lever, it transfers energy into a staple, which staplesthe
paper.A Bicycle is a compound machine. Screws are used to hold the
piecestogether and the seat adjustment is a screw. The wheels and
pedalseach form a separate wheel and axle system. The pedals are
attachedto a lever that turns a pulley. The brakes and brake
handles are levers.Can Opener is made up of 3 simple machines.
First is the wheel andaxle which is the handle, when you turn the
handle energy transfers tothe wedge which opens the can. Second is
the wedge, the thing thatslices open the can is the wedge. Lastly
is the lever, the arms of thecan opener are the levers. These two
levers open and close on onefulcrum to grip and help open the
can.