Post on 24-Dec-2015
Simple Machines
Helping us lift, lower, fasten, split, cut, divide, and move!
What is a Simple Machine?A simple machine
has few or no moving parts.
Simple machines make work easier
http://www.cosi.org/files/Flash/simpMach/sm1.swf
Simple MachinesThere are 6 simple machines
Wheel and AxlesPulleys Inclined PlanesWedgesScrewsLevers
Wheels and Axles A wheel and axle is a lever
that rotates in a circle around a center point or fulcrum.
The axle is a rod that goes through the wheel which allows the wheel to turn
Makes it easy to move things by lifting or rolling them, and reducing friction
http://www.cosi.org/files/Flash/simpMach/sm1.swf
Examples: car, bicycle, office chair, wheel barrow,
shopping cart, door handlehand truck, roller skates
Wheels and AxlesGears are a form of a wheel and axleA gear is a wheel with teeth. The teeth fit in between each other and
turn. When one gear turns, its teeth push
against the teeth of the other gear and they both turn.
There are gears on your bike, on a can opener and on an egg beater.
Pulleys Pulleys are wheels and
axles with a groove around the outside
A pulley needs a rope, chain or belt around the groove to make it do work
Makes lifting heavy weights easier by redirecting force
Pulleys let you move loads up, down, or sideways.
http://www.cosi.org/files/Flash/simpMach/sm1.swf
Types of Pulleys A fixed pulley is a pulley in
which the wheel does not move A moveable pulley does not change the direction of
the effort force but does increase the size of the force. When you pull on the rope, the pulley and the load come up.
A compound pulley, also called a block and tackle, is a combination of a fixed and a movable pulley. This type of pulley changes direction, and yields a gain in force at the same time.
Inclined Planes An inclined plane is a flat
surface that is higher on one end
Inclined planes make the work of moving things easier
Makes it easier to move objects upward; a longer path, but easier lifting
http://www.cosi.org/files/Flash/simpMach/sm1.swf
Wedges Two inclined planes
joined back to back. Wedges are used to
split things. Pushes material apart, cuts http://www.cosi.org/files/Fla
sh/simpMach/sm1.swf
Screws A screw is an inclined
plane wrapped around a shaft or cylinder.
The inclined plane allows the screw to move itself when rotated.
Turns rotation into lengthwise movement
http://www.cosi.org/files/Flash/simpMach/sm1.swf
Screws are inclined planes wrapped around a cylinder. They also act like a wedge albeit with just one edge to separate things. The more gentle the curving, the less force needed but it is needed over a longer distance. If you have tighter curving, you need more force and move less distance as the screw turns.
Levers-First Class In a first class lever the
fulcrum is in the middle and the load and effort is on either side
Helps lift heavy weights using longer distances
Think of a see-saw http://www.cosi.org/files/
Flash/simpMach/sm1.swf
Levers-Second Class In a second class
lever the fulcrum is at the end, with the load in the middle
Think of a wheelbarrow
Levers-Third Class In a third class lever
the fulcrum is again at the end, but the effort is in the middle
Think of a pair of tweezers
SUMMARYWedge Pushes material apart, cuts
Wheeland Axle
Makes it easy to move things by rolling them, and reducing friction
Lever Helps lift heavy weights using longer distances
Inclined Plane
Helps lift heavy weights using longer distances
Screw Turns rotation into lengthwise movement
Pulley Makes lifting heavy weights easier by redirecting force
Pulleys let you move loads up, down, or sideways.
Simple Machines Simple Machines
can be put together in different ways to make complex machinery
INVESTIGATE!
MiKids.com EdHeads.org Dirtmeister’s Simple Machines Simple Machines Complete the chart on the following slide with
your partner. Print out 1 copy.
These websites will help you learn more about Simple Machines.
After viewing these websites, you will be able to identify different types of each Simple Machine.
You will also be able to understand more about each type of Simple Machine.
Simple Machine
Diagram Describe how it worksAn unique example