Simple Machines

Group DD

Screw:A Simple Machine

By: Mike Zombro

What is a screw?

A screw is a simple machine that allows you to combine objects. It is usually made of steel and used to combine objects. They come in a large variety of sizes. A screw is used by twisting it into either a whole that is already made with a screwdriver or by making a whole with it using a drill.

Ideal mechanical advantage

The ideal mechanical advantage of a screw is for it to successfully hold two objects together. It holds them together by being screwed in a by a screwdriver in order for it to stay in place do to the spirals around the outside if the screw. This causes the screw to have a better hold on the two objects and causes it to not let go or come undone easily.

How does it change the force?

The screw changes the force because it goes from have two pieces of anything just there and then when the screw is placed in you combine these objects and they become 1 in that they will not come apart unless the screw is manually taken out, or they are broken apart with an even stronger force.

Mechanical Advantage

The formula for mechanical advantage is,

Output force

Input force

So if a it takes you 10n effort to put a screw into a piece of wood with a resistance of 5n the mechanical advantage would be 2.

Compound Machine #1

WedgesWedges

Alex DonmoyerAlex Donmoyer

What does it do?What does it do?

A wedge can be used to separate two A wedge can be used to separate two objects, lift an object, or hold an objects, lift an object, or hold an object in place.object in place.

How does it work?How does it work?

It works by converting a force applied It works by converting a force applied to its blunt end into forces to its blunt end into forces perpendicular to its length.perpendicular to its length.

Mechanical AdvantageMechanical Advantage

To find the mechanical advantage, To find the mechanical advantage, you take the length of the slope and you take the length of the slope and divide it by the thick part of the divide it by the thick part of the wedge.wedge.

For example, if the slope of the For example, if the slope of the wedge is 6 inches and the length of wedge is 6 inches and the length of the thick part is 2 inches, then the the thick part is 2 inches, then the mechanical advantage would be mechanical advantage would be three.three.

Scissors use two levers and the Scissors use two levers and the cutting edges are wedgescutting edges are wedges

The axe consists of a lever and a The axe consists of a lever and a wedge.wedge.

A screwdriver consists of a wheel and A screwdriver consists of a wheel and axel at one end and a wedge at the axel at one end and a wedge at the other.other.

BibliographyBibliography http://en.wikipedia.org/wiki/Scissorshttp://en.wikipedia.org/wiki/Scissors http://www.wealddown.co.uk/Shop/..%5Cimageshttp://www.wealddown.co.uk/Shop/..%5Cimages

%20shop%5C441axe.jpg%20shop%5C441axe.jpg http://www.cksinfo.com/clipart/construction/tools/http://www.cksinfo.com/clipart/construction/tools/

screwdrivers/red-screwdriver.pngscrewdrivers/red-screwdriver.png http://en.wikipedia.org/wiki/Wedge_(mechanical_device)http://en.wikipedia.org/wiki/Wedge_(mechanical_device) http://images.google.com/imgres?imgurl=http://http://images.google.com/imgres?imgurl=http://

www.realcheaptools.com/i/Wedges/www.realcheaptools.com/i/Wedges/Brass_Wedge.jpg&imgrefurl=http://Brass_Wedge.jpg&imgrefurl=http://www.realcheaptools.com/page/page/www.realcheaptools.com/page/page/4669076.htm&usg=__tESVg92DPUC1PbsHRRwiJwNT-4669076.htm&usg=__tESVg92DPUC1PbsHRRwiJwNT-CA=&h=187&w=300&sz=7&hl=en&start=4&um=1&tbCA=&h=187&w=300&sz=7&hl=en&start=4&um=1&tbnid=G2GgoXLdl_df6M:&tbnh=72&tbnw=116&prev=/nid=G2GgoXLdl_df6M:&tbnh=72&tbnw=116&prev=/images%3Fq%3Dwedge%2Bmechanical%2Bdeviceimages%3Fq%3Dwedge%2Bmechanical%2Bdevice%26hl%3Den%26safe%3Dactive%26sa%3DX%26um%26hl%3Den%26safe%3Dactive%26sa%3DX%26um%3D1%3D1

David HinklePd. 3

ExplanationA wheel and axle is a

lever that rotates in a circle around a center point or fulcrum.

EquationMA=r of wheel/r of Axle

Change in ForceThe change in force is when you apply force

to the axle to turn the wheel.For example:

A screwdriver is like a wheel and axle, the blade is wider then a screw, but it still takes some force to turn the screw if the handle was wider then it would be much easier to turn the screw.

Examples of Wheel and AxlesDoorknobsRoller SkatesFaucet handlesWagonToy CarScrewdriverFerris WheelWave swinger

Change in ForceThis simple machine

gets rid of energy released as vertical displacement, and it also gets rid of friction in the horizontal.

Mechanical Advantage of Wheels and AxlesIt has to deal with the ratio of the proportions

of the diameter of the axle and the wheel. For instance if the wheel is 4 times greater then the axle, then every time you turn the wheel the force will be 4 times greater for each turn.

Compound Machines w/ Wheels and AxlesBicycle

ScrewLeverPulley

Compound Machines w/ Wheels and AxlesWheelbarrow

Levers

Compound Machines w/ Wheels and AxlesCar

LeverPulleyInclined PlaneScrew

Bibliographyhttp://www.usoe.k12.ut.us/curr/science/sciber00/8th

/machines/sciber/machine7.htmThis website was a generic overview of what a wheel

and axle was use for and it demonstrates how a fulcrum works.

http://en.wikipedia.org/wiki/WheelThis was a complete background of how Wheels and

Axles came to be invented. And also where I got the mechanical advantage equation.

http://www.worsleyschool.net/science/files/wheel/andaxle.htmlThis site explained how screwdrivers and faucets are

considered wheels and axles because of what actions they perform.

Bibliography (Con’t)http://www.edinformatics.com/math_science/s

imple_machines/wheel_and_axle.htmThis site explained how the wheel and axle has a

mechanical advantage.

http://wiki.answers.com/Q/How_does_a_wheel_and_axle_change_its_forceThe change in force.

http://www.tecratools.com/media/productImages/ss_size1/17103.gifJust used this site for a picture.

Matt NolanPd. 3

A wheel that usually has a groove around the outside edge. This groove is for a rope or belt to move around the pulley. Pulling down on the rope lifts an object attached to the rope. Work is made easier because pulling down on the rope is made easier due to gravity.

MA=distance over which effort is applied distance over which the load Is

moved

3 Pulley Sytem that reduces the lifting force by 30 times.

This system allows you to pull a lot more weight then just one pulley.

Wedge,Pulley and InclineCompound machines

Wedge and Pulley The pulley in this picture helps to bring

the car up the incline of the wedge without the pulley there would be a lot more stress made trying to get the car up the block of wood.

Bicycle Wheel and Axle Screw Lever The pulley system

which helps turn the wheel easier without the pulley system you would not be able to turn the wheels. And the lever acts as the brake which is usually a hand brake.

www.edheads.org www.wikianswers,com www.edinformatics.com

Incline

Laura Blauch

Definition:

• An incline plane is a plane surface that is

set at an angle, which is not a 90 degree

angle, up on a horizontal surface, (ramp).

Mechanical Advantage of an incline…

• An inclined plane will help lower the amount of force needed to move an object a certain distance at an upward angle.

Inclines change force…

• Inclines can change the force of the object by changing the angle of the incline. The bigger the incline angle, the more force is needed to move the object.

Finding Mechanical Advantage…

• To find the mechanical advantage of an inclined plane you take the length of the incline divided by its height.

• Example: if an inclines length is 30m, and the height is 5m, what is the mechanical advantage of the incline?

Compound Machine #1

• Wheel barrel– Wheel and axle and incline

Compound Machine #2

• Escalator

• Gear and incline

Compound Machine #3

• Screw

• A spiral inclined plane, that has to be moving to work as an inclined plane.

Bibliography• http://www.edheads.org/activities/simple-machines/

– This website helped to show me what a compound machine of an incline could be, which is a wheel barrel. (used)

• http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/machines.htm– this website gave me a good definition of what a compound machine is.

(used) • http://washingtonville.ny.schoolwebpages.com/education/components/sectio

nlist/default.php?sectiondetailid=11887&PHPSESSID=5dfcae34f3a0b435b0579d594a2d6184– This website explained in more detail what exactly an incline works.

• http://www.weirdrichard.com/inclined.htm– This website showed me the mechanical advantage of an incline. (used)

• http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/machine2.htm– This website showed me more visual images of an incline plane.

LeverMursal Sekandari

Simple Machine: Lever

Lever is a simple machine. It consists of a bar that supports at some points along its length. At the second point, it is used to overcome resistance by applying a force at the third point. Fulcrum is the stationary point of which the lever rotates around. The basic principle of lever is two equal forces acting in the opposite directions.

Different Types of Class of Levers

There are three different classes of lever. First-class, Second-class Third class.

First-Class Lever A first-class lever has the

fulcrum located between the input effort and the output load.

Force is applied by either pulling or pushing, which causes the lever to swing and overcoming the resistance force on the opposite side.

Second-Class Lever In a second class lever,

the fulcrum is located at the end of the bar and the input effort is located at the other end of the bar.

Third-class Lever In third class levers, effort

is applied between the output load on one end and the fulcrum on the opposite end.

This one is different than the other two class levers because the input is higher than the output load.

Examples of a Lever First-class

Hammer claw Sea-saw Bicycle hand

brake Scissors Wheel and

axle

Second Class Paddle Bottle openers Doorknobs Nutcrackers Wrench

Third Class Baseball bat Shovel Thongs Tweezers Hammer Nail clipper Fishing rod

Advantage of this simple machine Some advantage of using

this simple machine is picking up a heavy rock, or using it to lift the television. It is also used to have fun at the park, sea-saw. Or as illustrated in this picture, a can of paint.

Equation: effort arm

resistance arm

Changing force The simple machine changes the force by

applying effort on one side and the load also receiving the force and moving as well.

Example When watching a circus act, you notice the

tumblers using a first class lever and wonder how if one of them jumps, it can propel two of them into the air. When the tumbling lever is measured, it shows the effort arm is 8 meters long, the resistance arm is 2 meters long.  What is the mechanical advantage of this lever? To do this problem you have to know what equation

to use. MA = effort arm / resistance arm

MA = 8m / 2m MA = 4

Compound Machine #1: Scissors

Compound Machine #2:

Compound Machine #3:

Bibliography http://library.thinkquest.org/J002079F.lever.htm

It just simply told me about what a lever is and the three types of class. Http://library.thinkquest.org/C004451F/nflever.htm

It provides information that helps to explain lever further more. http://www.edheads.org/activities/simple-machines/

It gave examples of compound machines. http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machine

s/sciber/machines.htm Helped me with learning what the difference is between simple and

compound machines. http://www.sandiegostc.org/met/science/ps/pmachine.htm

This site had information on compound and simple machines.