Simple Machines

Group GG

ScrewScrew

A screw is a simple machine that is made from another A screw is a simple machine that is made from another simple machine. It is actually an incline plane that simple machine. It is actually an incline plane that

wraps around itself, it has ridges and is not smooth like wraps around itself, it has ridges and is not smooth like a nail. Screws are used to lower and raise things and a nail. Screws are used to lower and raise things and

they are also used to hold things together.they are also used to hold things together.

screwsscrews

Mechanical Advantage Mechanical Advantage

• Circumference / pitch

• Mechanical advantage of a screw can be found by dividing the circumference of the screw by the pitch

Example of mechanical advantage Example of mechanical advantage

• Placing a ruler next to a screw and count 10 threads, the pitch of the screw would be 1/10

Compound machineCompound machineScrew is usedScrew is used

A sign…….A sign…….

A Screw is used in this picture.

a compound machine!a compound machine!

And again, a screw is used.

BibliographyBibliography

• http://www.manatee.k12.fl.us/sites/elementary/samoset/technology/Screw.htm ( Provided pictures of the simple machine at work in a compound machine)

• http://www.edheads.org/activities/simple-machines/ (Showed all the simple machines and what they are used for)

• http://www.mikids.com/Smachines.htm (Provided a definition of screw)

• http://www.coe.uh.edu/archive/science/science_lessons/scienceles1/screw.htm

• http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm (found the mechanical advantage of a screw, and also found the example)

The Lever

“Simple Machines”

Erika Blauch

Lever

A lever is a simple machine that allows you to move a load around a pivot using a force

It is used to make work easier

A lever changes the force

A lever changes the force by allowing the user to shift the weight of the object by using the fulcrum. This makes the object easier to lift and move.

First Class Lever

A first class lever is when the

fulcrum is located in between the effort and the

load.

Second Class Lever

A second class lever is when the effort and load are located on the same end,

while the fulcrum is located on the

other.

Third Class Lever

A third class lever is when the load is located on one

end and the fulcrum on the other, while the

effort is applied in between.

Effort ArmResistance Arm

MA = Effort Arm

Resistance Arm

*Distances are measured from the load or effort to the fulcrum

MA= Resistance

Effort

*Use this if you are given the Amount of resistance and the amount of Effort

Equation to find the ideal mechanical advantage

Amount of resistance

Am

ount

of

Effo

rt

*Use this if you are given the distances from the load and effort to the fulcrum

Problem

A man wants to lift a heavy rock by using a lever. MA = Effort Arm

Resistance Arm

20m

10m

Effort Resistance

20 m10 m

The mechanical advantage is 2

Compound machine (1st class)

A seesaw is a compound machine that contains the lever, screw, and the wheel and axle.

Compound machine (2nd Class)

A wheel barrow is a compound machine that contains the lever, and the wheel and axel.

Compound machine (3rd Class)

A construction crane is a compound machine that contains wheel and axle and a lever.

Bibliography

http://www.enchantedlearning.com/physics/machines/Levers.shtml This site had the moving pictures for first, second, and third class

levers. www.bestinc.org/docs/Survival_Guide/education_resources/

engineering_mechanics.pdf www.imaginationfactory.questacon.edu.au/assets/

im_levers.pdf This site showed how the different types of classes work

http://www.edinformatics.com/math_science/simple_machines/lever.htm

http://www.tpub.com/content/engine/14037/css/14037_15.htm This site had the mechanical advantage of the lever

Inclined PlaneBy Becky Guldin

According to Webster…An inclined plane is

Main Entry: inclined plane

Function: noun

Date: 1710

: a plane surface that makes an oblique angle with the plane of the horizon

Mechanical Advantage Mechanical Advantage = Slope/Height

Inclined Plane An inclined plane changes the force by

allowing “one to overcome a large resistance by applying a relatively small force.”

Inclined Plane Example What is the mechanical advantage of a

plane with an incline of 15 feet and a height of 10 feet?

MA= slope/height MA=15 ft / 10 ft MA= 3/2 or 1.5

The Johnstown Incline Inclined Plane Pulley Wheel and Axel Screw

A Roller Coaster Inclined Plane Screw Pulley Wheel and Axel

Roller Slide Inclined Plane Wheel and Axel

Bibliography http://www.merriam-webster.com/dictionary/inclined%20plane

Used to find a definition of “inclined plane” http://74.125.47.132/search?q=cache:sYtg9veBsB8J:www.uark.edu/depts/aeedhp/

agscience/simpmach.htm+mechanical+advantage+inclined+plane&hl=en&ct=clnk&cd=1&gl=usUsed for information on an incline’s mechanical advantage

http://www.weirdrichard.com/inclined.htmbUsed to find how an inclined plane changes force

http://images.google.com/images?hl=en&q=johnstown+incline&safe=active&um=1&ie=UTF-8&sa=N&tab=wiUsed for pictures of inclined plane

http://images.google.com/images?um=1&hl=en&safe=active&q=inclineUsed for pictures

**all five sources used

Wheel and Axle Wheel and Axle

Simple Machines ProjectSimple Machines Project

Dominic DiAngelisDominic DiAngelis

Definition of a wheel and axleDefinition of a wheel and axle

a simple machine consisting, in its typical a simple machine consisting, in its typical form, of a circular object that rotates form, of a circular object that rotates on/around a smaller circular object. The on/around a smaller circular object. The outer object is known as the wheel, and outer object is known as the wheel, and the smaller inner object serves as the axle. the smaller inner object serves as the axle. The axle is placed in the center of the The axle is placed in the center of the wheel in order for the two pieces to act wheel in order for the two pieces to act with each other with each other

Basic DiagramBasic Diagram

How it worksHow it works

Wheels help you move an object across a Wheels help you move an object across a surface because they cut down on the amount of surface because they cut down on the amount of friction between what you're trying to move and friction between what you're trying to move and the surface you're pulling it against. Though the the surface you're pulling it against. Though the entire circumference touches the ground at one entire circumference touches the ground at one point or another the weight is focused on the point or another the weight is focused on the bottom most portion. Because only a small bottom most portion. Because only a small portion touches the ground the surface area is portion touches the ground the surface area is decreased, therefore also decreasing the decreased, therefore also decreasing the amount of friction between the surface and the amount of friction between the surface and the object. object.

ApplicationsApplications

Wheels and axles are used generally in any Wheels and axles are used generally in any situation where an object which would situation where an object which would otherwise have too great of friction without otherwise have too great of friction without the use of wheels to be moved. Wheel the use of wheels to be moved. Wheel and axle applications. range anywhere and axle applications. range anywhere from simple wagons to $300,000 Ferraris.from simple wagons to $300,000 Ferraris.

Mechanical AdvantageMechanical Advantage

The mechanical advantage of a wheel and The mechanical advantage of a wheel and axle can be found by finding the ratio of axle can be found by finding the ratio of the wheel’s radius to the axle’s radius. the wheel’s radius to the axle’s radius.

MA = wheel’s radius MA = wheel’s radius ÷ axle’s radius÷ axle’s radius

MA diagram

MA is = Wheel radius : axle radius The MA of the wheel and axle in this

diagram is 5:1 or 5

Ex. problem

If a Ferrari’s axle has a 2.5 in radius and the wheel/tire have a radius of 11in what is the mechanical advantage of the wheel/axle.

Answer to ex. problem

Because the wheel has a radius of 11in and the axle has a radius of 2.5in the MA is 4.4

Compound machines including Compound machines including wheel and axles. wheel and axles.

A wheelbarrow uses three simple A wheelbarrow uses three simple machines, a wheel and axle, lever, and machines, a wheel and axle, lever, and inclined plane. inclined plane.

Compound machines cont.

This Lamborghini uses every single simple machine. Levers, pulleys, inclined planes, wheel and axle, wedges, and screws.

Assembly line rollersAssembly line rollers

These rollers use wheel and axles, These rollers use wheel and axles, inclined planes, and screwsinclined planes, and screws

Bibliography

http://www.edheads.org/activities/simple-machines/ examples and definitions of the simple machines

http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm mechanical advantage of the simple machines

http://teacher.scholastic.com/dirtrep/simple/wheel.htm description of the wheel and axle

http://science.jrank.org/pages/4056/Machines-Simple-Wheel-axle.html description of the wheel and axle

Physics Project: Simple Machines

PulleysPulleys

Alex BailorAlex Bailor

Pulleys

A pulley is simply a grooved wheel that rotates freely within a block of wood.

A pulley has a piece of rope attached to it. A pulley changes the direction of force in order to gain a

mechanical advantage. A pulley can either be fixed or movable.

Fixed Pulleys

A fixed pulley does not move with the load being moved. It changes a direction of force but it does not create a

mechanical advantage.

Moveable Pulleys

A moveable pulley moves with the load that is being moved.

It creates a mechanical advantage but it does not change the force of direction.

Block and Tackle

A block and tackle uses both fixed and moveable pulleys. It is able to create a mechanical advantage and change the

direction of force.

Mechanical Advantage

The mechanical advantage of a pulley system is the number of ropes used to move it meaning every time the rope changes direction, count it as a new rope.

If the load is being pulled upwards, count all of the ropes. If the load is being pulled downwards, subtract one from

the total number of ropes.

Mechanical Advantage cont.

Example: This pulley system has a mechanical advantage of 6.

7 ropes – 1 rope = 6

Mechanical Advantage cont.

The pulley changes the force of direction in order to make the effort less.

For example, if you use two pulleys instead of one, you cut the force required to move the object in half, BUT you double the amount of rope that you need in order to move the object

Mechanical Advantage Problem

What is the mechanical advantage of this pulley system? Answer: 4

Rope starts here

Compound Machine 1

This crane uses a pulley, an inclined plane, and a lever.

Compound Machine 2

This bicycle uses a pulley, wheel and axle, and lever.

Compound Machine 3

The Johnstown Inclined Plane uses an inclined plane, a wheel and axle and a pulley.

Bibliographyhttp://www.uark.edu/depts/aeedhp/agscience/simpmach.htm

This website gives a very in depth explanation of all simple machines. It also explains how to find the mechanical advantage and it goes into the different variations on the pulley. This website also provides pictures.

http://www.encyclopedia.com/topic/block_and_tackle.aspx This website gives a general overview of how a block and tackle works. It

also provides pictures.http://teacher.scholastic.com/dirtrep/Simple/pulley.htm

This website also gives a general overview of a pulley but it also informs the reader on how to find the mechanical advantage of a pulley.

http://www.swe.org/iac/lp/pulley_03.html This website gives a very in depth explanation of the history of a pulley. It

also explains how to find the mechanical advantage of a pulley.http://www.technologystudent.com/gears1/pulley7.htm

This website shows how a pulley works and it also explains how to find the mechanical advantage.

I used all of these websites in my PowerPoint.

Wedge

Samantha Imler

Explanation of a wedge

• A wedge is an inclined plane that moves. A knife, axe, razor blade, and teeth are some good examples of wedges.

• Instead of moving things a wedge helps you move things apart like a knife or split things like wood.

Wedge

• In this pencil sharpener the wedge is the blade.

• It sharpens the pencil to make it able to write with the pencil.

Mechanical advantage

• The mechanical advantage of a wedge is given by the ratio of its length to its width. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle.

• The equation it l/w• For example in the picture to

the side L would be 5 inches and t would be 2 inches so the ratio would be 5/2.

Compound Machines

• The compound machine uses a wedge and screw to put holes into wood or anything else you need to put a hole in.

Pencil Sharpener

• The pencil sharpener uses the simple machines wedges and levers.

Snow blower

• This snow blower uses the simple machines wedge and a wheel and axel.

Bibliography

• http://www.usoe.k12.ut.us/curr/science/sciber00/8th/machines/sciber/machine3.htm *

• http://www.weirdrichard.com/wedge.htm *• http://teacher.scholastic.com/dirtrep/simple/wedge.htm *• http://en.wikipedia.org/wiki/Wedge_(mechanical_device) *• http://www.northstar.k12.ak.us/schools/upk/projectsfolder/gold/facts/

machines/machines.html• * websites that I did use.