Simple Machines Slide Presentation

7/29/2019 Simple Machines Slide Presentation

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WORK

ENERGY

MACHINES

POWERHow fast work is done Capacity to do work

Makes work easier

Force acting through a

distance


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Instrumentthat makes

work

easier


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WORK

is the transfer of energy fromone physical distance to

another Measured in Joules

W = F x dWork = Force x Distance


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What is MechanicalAdvantage?

Number of times a machinemultiplies the effort force

Tells how much force is

gained by using machine


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The force you exert on the machine is called the input force or the effort force. The force exerted by

the machine is called the output force or the resistance force.

If you compare the input force to the output force, you can determine the advantage of using a

machine. A machines mechanical advantage is the number of times a force exerted on a machine is

multiplied by the machine.

A machine makes work easier by changing the

amount of force you exert, the distance over which

you exert your force, or the direction in which you

exert your force.


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TYPES OF WORKA.INPUTwork that goes into

the machineneeds effort force


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B.OUTPUTWork done by (out of)

the machine

ResistanceForce


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WORK = FORCE x DISTANCE

WORK INPUT WORK OUTPUT

INPUT = OUTPUT

EFFORT

FORCEDISTANCE

OUTPUT

FORCEDISTANCE

Multiply

the force

Change distance

overwhich force isexerted

Change

in Direction


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Machines do notincrease workoutput

Work output is never greater

than work input


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Work in = Work out

Work input (force to move something overa distance)

Work output (force from the machine to

move something over a distance)

Machines make work easier because theychange either the _________ , _________or _________of the force put into themachine.


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LeverA bar free to pivot, or

rotate about a fixed point(fulcrum)

Inclined PlaneA flat, slanted surface

ScrewTwisted

inclined plane

WedgePortable/moving

inclined plane

Wheel andaxle

Circular lever

(axle is fulcrum)

PulleyA wheel revolving

freely around an

axle

GearToothed wheel

that fit into one

another


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LEVERS Simple machines used to lift

weights


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First Class LeversAn example of this type is a

seesaw.


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Second Class LeverThe difference from the

first class lever is that the

fulcrum is on the end,instead of in the middle.


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Third Class Lever

The load is the fish; the handle

end is the fulcrum.


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INCLINEDPLANE


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Inclined Plane- A simple machine that makes it

easier to move a heavy object to a

higher or lower elevation.

- It reduces the amount of force

needed to lift the object.


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The Egyptians used inclined

planes to build the pyramids.


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WEDGES

A wedge is a simple machineshaped like an inclined plane.

It is like aportable inclined

plane.


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SCREWSA screw is a cylinder with an inclined

plane wrapped around it.
http://library.thinkquest.org/J002079F/plane.htmhttp://library.thinkquest.org/J002079F/plane.htmhttp://library.thinkquest.org/J002079F/plane.htmhttp://library.thinkquest.org/J002079F/plane.htm


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Archimedes Screw

Archimedes of

Syracuse, when he wasin Egypt, invented a

machine for pumping

bilge water out of the

holds of ships.


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WHEEL AND AXLE

made up of two circular objects of

different sizes

Smaller

Object (axle)

Larger

Object

(wheel)


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Pulley

A wheel revolving freely

around an axle


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Mechanical Advantage = Output Force

Input Force

Examples:

Inclined Plane:

M.A. = Load

Effort

= 5N/0.2N

= 25

Pulley:

M.A. = Load

Effort

= 6.5N/1.5N

= 4


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Output workInput work x 100%

Efficiency of the machine =

Expressed as a percentage

EFFICIENCY

Simple Machines Slide Presentation

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