6 Simple Machines By: Emma Dillon Miles Taylor Jack Yau Kevin Lynch Table of Contents Simple Machines Compound Machines Inclined Plane Wedge Screw Lever Wheel and Axle Pulley More Videos Acknowledgments (resources) Simple Machines by: Emma Dillon There are six basic machines; the inclined plane, wedge, screw, lever, wheel and axle, and the pulley. Simple Machines Video Back to Table of Contents Compound Machines by: Miles Taylor A compound machine is a machine that consists of two or more simple machines. Example: Bicycle. It has a pulley for the bike chain, two wheels and axles, levers for the hand brakes, and screws to hold it together. Back to Table of Contents Inclined Plane • by Emma Dillon An inclined plane is a flat slanted surface whose endpoints are at different heights. An inclined plane lets you exert your input force over a larger distance. That way, the input force will be less than the output force. How to determine the ideal mechanical advantage of an inclined plan: Length of incline _______________ = ideal mechanical advantage Height of incline Back to Table of Contents More Information Uses: You use it to lift objects from lower levels to higher levels. An example is a ramp. Values: One value of the inclined wedge is that it reduces work due to friction. You increase the efficiency of an inclined plane by decreasing the friction. Back to Table of Contents Wedge by: Emma Dillon A wedge is a device that is thick at one end and tapers to a thin edge at the end. Wedges are inclined planes two of them back to back that can move. The longer and thinner the wedge, the less input force is required to do the same amount of work. In a wedge, instead of an object moving along the inclined plane, the inclined plane moves itself. How to determine the mechanical advantage of the wedge: Length of sloping side =mechanical advantage Length of thick end Back to Table of Contents More Information Uses: A wedge uses force to come between two objects. It is used for three different types of work: splitting, connecting, and tightening. Examples of wedges are axes, nails, doorstops, and zippers. Values: • • There are many values of the wedge. When using a wedge, a small force is multiplied to do the job. This is good because it reduces the amount of the input force, the force that you have to put in. Back to Table of Contents Screws A simple machine that is related to the inclined plane. It can be thought as an inclined plane wrapped around a cylinder. When you use a screwdriver to twist a screw into a piece of wood, you are exerting an input force on the screw. When you turn the screw into the wood, the screw exerts an output force on the wood. The mechanical advantage of a screw can be found by dividing the circumference of the screw by the pitch of the screw. by: Jack Yau Back to Table of Contents Levers A lever is a rigid bar that is free to pivot, or rotate, about a fixed point. The fixed point that a lever pivot around is called the fulcrum. Think about a lever like a paint can opener, the opener is resting against the edge of the can acts, as a fulcrum. The tip f the opener is under the lid of the can. You push down on the opener, exerting an input force, and the opener pushes the lid up, exerting an output force on the lid. To calculate the ideal mechanical advantage , you have to divide the distance from fulcrum to input force by distance from fulcrum to output force. by: Jack Yau Back to Table of Contents History of Wheels by: Kevin Lynch The English word wheel comes from the Proto-IndoEuropean *kwekwlo-,[1] which was an extended form of the root *kwel- meaning "to revolve, move around". This is also the root of the Greek κυκλος kuklos, the Sanskrit chakra, and Persian charkh, all meaning "circle" or "wheel",[2] and also in Lithuanian, sukti means "to rotate". The Latin word rota is from the Proto-Indo-European *rotā-, the extended o-grade form of the root *ret- meaning "to roll, revolve".[3] Back to Table of Contents History of Axle History of Axle by: Kevin Lynch An axle is a central shaft for a rotating wheel or gear. In some cases the axle may be fixed in position with a bearing or bushing sitting inside the hole in the wheel or gear to allow the wheel or gear to rotate around the axle. In other cases the wheel or gear may be fixed to the axle, with bearings or bushings provided at the mounting points where the axle is supported. Sometimes, especially on bicycles, the latter type is referred to as a spindle. Back to Table of Contents Wheels (cont.) Ideal MA= radius of wheel/ radius of axle Actual MA= R/E actual Screwdrivers, doorknobs, windmills, gears, and Chain Falls are all examples of the wheel and axle. Back to Table of Contents History of levers by: Kevin Lynch First class levers: A first-class lever is a lever in which the fulcrum is located in between the input effort and the output load. Second class levers: In a second class lever the input effort is located at one end of the bar and the fulcrum is located at the other end of the bar, opposite to the input, with the output load at a point between these two forces. Third class levers: It is to be noted that for this class of levers, the input effort is higher than the output load, which is different from the first-class and second-class levers. Back to Table of Contents History of the Axle Facts About Levers Lever: In physics, a lever (from French lever, "to raise", c.f. a levant) is a rigid object that is used with an appropriate fulcrum or pivot point to multiply the mechanical force that can be applied to another object. This is also termed mechanical advantage, and is one example of the principle of moments. A lever is one of the six simple machines. Back to Table of Contents More on Wheels The Pulley by: Miles Taylor The pulley is a machine that consists of one or more wheels with grooves, and rope. To operate the pulley, put the rope in the groove and hang the wheel on something. Now apply downward pressure, or pull on the rope. The rope on the other side should raise, along with whatever it is attached to. There are many different kinds of pulleys- fixed pulleys, movable pulleys, and compound pulleys. Fixed pulleys are when the wheel doesn’t move, a movable pulley is when the wheel does move, and a compound pulley is when there are multiple wheels. The mechanical advantage of the fixed pulley is 1. The machanical advandahe of the movable pulley is 2 For compound pulleys, add the multiple for each wheel. For instance. 2 wheels: 2. 3:3. 4:4 and so on… Back to Table of Contents More Videos http://youtube.com/watch?v=C-UXry70iXM http://youtube.com/watch?v=sOikTpFgi3Y Back to Table of Contents Information Resources Science Explorer; Motion, Forces, and Energy ---(information on the wedge and inclined plane) http://www.fi.edu/pieces/knox/automaton/wedge.htm --(information on the wedge) http://en.wikipedia.org/wiki/Wedge_(mechanics) --(information on the wedge’s mechanical advantage) http://en.wikipedia.org/wiki/Wheel#History_of_the_wheel_an d_axle Back to Table of Contents Picture Resources Picture Resources Inclined plane: More Resources http://images.google.com/imgres?imgurl=http://physics.kenyon.edu/EarlyAppa ratus/Mechanics/Inclined_Plane/ebay1.JPG&imgrefurl=http://physics.kenyon. edu/EarlyApparatus/Mechanics/Inclined_Plane/Inclined_Plane.html&h=325& w=450&sz=20&hl=en&start=2&tbnid=Jb2q2Nrei7LfCM:&tbnh=92&tbnw=1 27&prev=/images%3Fq%3Dinclined%2Bplane%26gbv%3D2%26svnum%3D 10%26hl%3Den Second Inclined Plane: http://www.blueberryforest.com/images/Images_ct/kinderkram-40513-ramp389.jpg Wedge Picture: http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/images/wedge.j pg Zipper Picture: http://www.wpclipart.com/clothes/zipper_2.png Ax and Nail Picture: Clip Art Back to Table of Contents Picture Resources (Cont.) Screw Picture: http://www.artestuff.com/images/screw-standard.jpg Lever Picture: http://www.sciencebyjones.com/Firce_class_lever_drawing.gif Bike Picture: http://weightweenies.starbike.com/images/lightbike/bike.jpg Simple Machines Pictures: Pulley; http://www.indiainnovates.com/images/products/pulley_stopper.jpg Wedge; http://www.brantacan.co.uk/WedgeActionMW.gif Inclined Plane; http://dots.physics.orst.edu/graphics/image_maps/inclined_plane.gif Lever; http://www.techsploration.com/Lever2.JPG Screw; http://faq.f650.com/FAQs/Photos/ChainPhotos/ChainGuardScrew.jpg Wheel and Axle; Back to Table of Contents http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/images/logo.gif