- published: 13 Nov 2014
- views: 35846
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. In nautical contexts, the assembly of wheel, axle, and supporting shell is referred to as a "block."
A pulley may also be called a sheave or drum and may have a groove between two flanges around its circumference. The drive element of a pulley system can be a rope, cable, belt, or chain that runs over the pulley inside the groove.
Hero of Alexandria identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.
A set of pulleys assembled so that they rotate independently on the same axle form a block. Two blocks with a rope attached to one of the blocks and threaded through the two sets of pulleys form a block and tackle.
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines which were defined by Renaissance scientists:
A simple machine uses a single applied force to do work against a single load force. Ignoring friction losses, the work done on the load is equal to the work done by the applied force. The machine can increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the applied force is called the mechanical advantage.
Simple machines can be regarded as the elementary "building blocks" of which all more complicated machines (sometimes called "compound machines") are composed. For example, wheels, levers, and pulleys are all used in the mechanism of a bicycle. The mechanical advantage of a compound machine is just the product of the mechanical advantages of the simple machines of which it is composed.
Actors: Eugene Levy (actor), Steven Weber (writer), Jayne Eastwood (actress), Alan Alda (actor), Peter Riegert (actor), Steven Weber (producer), Boyd Banks (actor), Louis Di Bianco (actor), Jack Duffy (actor), Brad Garrett (actor), Harvey Atkin (actor), Steven Weber (actor), Sam Malkin (actor), Saul Rubinek (director), Ruth Secord (costume designer),
Genres: Drama,Actors: Yoram Globus (producer), James Hong (actor), Misha Segal (composer), Menahem Golan (producer), T.J. Castronovo (actor), Dale Ishimoto (actor), Sam Firstenberg (director), John LaMotta (actor), Jay Rasumny (actor), Shô Kosugi (actor), Randy Mulkey (actor), Ron Foster (actor), Steven Lambert (actor), Udi Harpaz (composer), Earl W. Smith (actor),
Plot: The body of a sexy aerobics instructor is invaded by the evil spirit of a dying ninja. At first, changes in her behavior is limited to having strange interactions with an arcade game, doing sexy things with V8 juice, and being attracted to an unusually hairy police officer. But soon enough, she's systematically killing, ninja-style, the officers responsible for the ninja's death, and can only be stopped by another ninja!
Keywords: b-movie, blood, blood-spatter, bo-staff, brawl, chase, chop-socky, cult-film, curse, death0:00 Working Class Whore 3:33 Soberbeah 5:48 Pie 9:00 Gone 11:22 Over It 14:15 Darkside 16:36 Nothing To Lose 19:37 Second Best 21:28 Just For Me 23:26 Dog's Life 25:30 Sick 27:50 Intro – Outro
0:00 A Bad Reputation 2:53 Blindfold 5:37 Huber Breeze 8:02 Insects Destroy 11:23 Looking Back 14:12 Poltergeist 16:28 Immune 20:52 YSC 24:01 Stomach Aches 26:52 I Remember 29:12 Suitcase 32:25 Thanks
Simple Machines lesson for 3rd grade unit. From Disney's Bill Nye the Science Guy. Levers, pulleys, and wheels. Also clips from Eureka!, a 1980 animated short series from Toronto. Music by John Williams
1- "Cashed In" 2- "Crawl" 3- "Eyes Open Wide" 4- "Wok Inn" 5- "Four Walls" 6- "One Shot" 7- "Barf" 8- "She" 9- "Lifer" 10- "No Defense" 11- "Silver Tongue Devil" 12- "S.F.B.I.H.Y.D." 13- "Seain' Different" 14- "All We Have"
http://mocomi.com/ presents: What is a Pulley? Pulley is a simple machine and comprises of a wheel on a fixed axle, with a groove along the edges to guide a rope or cable. Pulleys are used to reduce the time and energy taken to lift heavy objects. Here, Load = the weight of an object Effort = the amount of force required to lift or move this object. When you put two or more wheels together, and run a rope around them, you have created a great lifting machine. As you add more pulleys, you increase your mechanical advantage and it becomes very easy to lift the same load. The trade-off is that as you increase the number of pulleys, you require a greater amount of rope to achieve the same result. Since you have decreased the effort needed to lift the load you have to apply the force for...
Learn how snatch blocks and wire rope can work to your advantage. Watch Terry Abejuela, American Towman's Field Editor, explain the basics of pulley systems for towing. This video is brought to you by Towlot.com, the site that makes your profitable online vehicle auctions a snap.
Make a hand operated pulley setup to test some small motors for generating potential (subtitles in English) Hacer una polea manual para probar motores pequenos por su potencial de generar energia.(subtitulos en Espanol)
has the power and he's going nowhere,
what is left to ruin?
to the start of something, i'm not buying,
i expect the ruins. you can take my isolation,
also take the pain it brings.
can you move the walls the hold me?
tear them down from everything.
the reason for the grimaced face is what you've had to see.
the other day a story's told to me,
i don't think i listened.
without you things they wouldn't be this way,
can't you make me listen?
think for now i'll fly the seat i fly,
let my imagination grow.
people say i waste my life,
cross my bridges as the burn.
never look back with intentions,
looking back, with no concern.