simple machines. simple machines are "simple" because most have only one moving part....
TRANSCRIPT
Simple Machines
Simple Machines Simple machines are "simple" because
most have only one moving part. Machines do not reduce the amount of
work for us, but they can make it easier. When simple machines are put together
they create complex machines Machines have a mechanical advantage,
the amount of output should be greater than the amount of input effort.
Six types of Simple Machines
Inclined Plane Lever Wheel & Axle Pulley Screw Wedge
Lever LEVER: A stiff bar that rests on a support called a
fulcrum. How it works: Lifts or moves loads. Examples: There are three types of levers.
A first class lever is like a teeter-totter or see-saw. One end will lift an object up just as far as the other end is pushed down.
A second class lever, the load arm lies between the fulcrum and the force arm. A good example of this type of lever is the wheelbarrow.
A third class lever has the effort between the load and the fulcrum. Both the effort and load are in the same direction. Note that the length of the load arm goes all the way to the fulcrum and is always greater than the length of the effort arm. Tweezers are an example.
Parts of a LeverA typical lever consists of a solid board or rod that can pivot about a point or fulcrum. A force or effort is applied, resulting in moving or applying force to a load. The distance from the applied force or effort force to the fulcrum is called the effort arm and the distance from the load to the fulcrum is called the load arm.
Classes of Levers Class 1
Class 2
Class 3
Inclined Plane INCLINED PLANE : An inclined plane is a straight
slanted surface connecting a lower level to a higher level at an angle.
How it works: The inclined plane is simply a flat surface raised at an angle, like a ramp. It is a way of lifting a load that would be too heavy to lift straight up.
The angle (the steepness of the inclined plane) determines how much effort is needed to raise the weight. The steeper the ramp, the more effort is required.
Example: Ramp, slide, stairs, escalator
Wheel & Axle WHEEL AND AXLE : A wheel and axle is a modification
of a pulley. A wheel is fixed to a shaft. The wheel and shaft must move together to be a simple
machine. How it works: Lifts and moves loads of material. Examples: bicycle, doorknobs, pencil sharpener.
Pulley PULLEY: A pulley is a simple machine made with a
rope, belt, or chain wrapped around a grooved wheel. How it works: A pulley works two ways. It can change
the direction of a force or it can change the amount of force. A fixed pulley changes the direction of the applied
force.
( Ex. Raising the flag ) A movable pulley is attached to the object you are
moving. Examples: Curtain rod, tow truck, flagpole, crane
Wedge WEDGE: A wedge is a modification of two inclined plane
that move. How it works: A wedge is made of two inclined planes
put together. Instead of the resistance being moved up an inclined plane, the inclined plane moves the resistance.
Examples: Axe blade, car tire wedge, chisel, nail
Screw SCREW: A screw is a simple machine that is like an
inclined plane. It is an inclined plane that wraps around a shaft.
How it works: A screw works by turning it into an object or flat surface. Then the threads (incline plane) that are around the shaft crush through the object.
Examples: Screw, nuts, bolts, jar lip, light bulb end
Summary
Simple machines are "simple" because most have only one moving part.
Machines do not reduce the amount of work for us, but they can make it easier.
"Work" is only done when something is moved.
Work is the product of effort and distance.
ORGANIZER SIMPLE
MACHINES WHAT IT IS HOW IT WORKS EXAMPLES
LEVER A stiff bar that rests on a support called a fulcrum.
Lifts or moves loads
1st- Teeter totter2nd- Wheel barrow3rd- Tweezers
INCLINED PLANE
A slanting surface connecting a
lower level to a higher level.
Things move up or down it
Slide, stairs, ramp, escalator
WHEEL AND AXLE
A wheel with a rod, called an
axel, through its center: both parts
move together.
Lifts or moves loads
Doorknob, pencil sharpener, bike
ORGANIZER SIMPLE
MACHINES WHAT IT IS HOW IT WORKS EXAMPLES
PULLEY A grooved wheel with a rope or
cable around it.
Moves things up, down, or across
Curtain rod, tow truck, flag pole,
crane
WEDGE A type of inclined plane with a sharp edge. The wedge
moves, the inclined plane
stays still.
Pushes things apart
Axe blade, nail, car tire wedge
SCREW An inclined plane wrapped around a
cylinder.
Raises weights, presses or fastens
objects
Screws, nuts
Name/period: _____________________________
SIMPLE MACHINES SIMPLE
MACHINES WHAT IT IS HOW IT WORKS EXAMPLES
LEVER
INCLINED PLANE
WHEEL AND AXLE
SIMPLE MACHINESSIMPLE
MACHINES WHAT IT IS HOW IT WORKS EXAMPLES
PULLEY
WEDGE
SCREW