1 / 57

Simple Machines

Simple Machines. Group EE. Wheel and Axle. Nicole Teasdale Pd: 3 Date: 2/26/09. Wheel and Axle.

selima
Download Presentation

Simple Machines

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Simple Machines Group EE

  2. Wheel and Axle Nicole Teasdale Pd: 3 Date: 2/26/09

  3. Wheel and Axle • The wheel and axle is a simple machine. The wheel and axle consists of a hand wheel (a disc or lever arm with a handle) which turns an axle around which a chord is wound. A heavy weight attached to the chord can be lifted more easily because of mechanical advantage.

  4. Wheel and Axle

  5. Wheel and Axle • The mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle. If the radius of the wheel is four times greater than the radius of the axle, every time you turn the wheel once, your force will be multiplied four times.

  6. Example of finding Mechanical Advantage • The ideal mechanical advantage of a wheel and axle is calculated with the following formula: • Actual mechanical advantage • The actual mechanical advantage of a wheel and axle is calculated with the following formula: • where • R = resistance force, i.e. the weight of the bucket in this example. • Eactual = actual effort force, the force required to turn the wheel.

  7. Wheel and Axle • The wheel & axle can be used as a tool to multiply the force you apply, or to multiply the distance travelled. Here's how it worksYou apply a force on the wheel, whose radius R is larger than the axle.The force is transmitted to the axle, which has radius r.This resultant force, which is bigger than the force you applied, does some work for you.The force that does the work is bigger by a factor of  R/rFor example, if the wheel is 10 times wider than the axle, the resultant force will be 10 times bigger.

  8. Wheel and Axle • Wheel & axle can also be used in reverse. You apply force to the axle, to make the wheel turn.This doesn't seem to make much sense.. you'll have to apply a much larger force, to produce a relatively small resultant force.

  9. Compound Machines • Compound machines are two or more simple machines working together. A wheelbarrow is an example of a complex machine that uses a lever and a wheel and axle. Machines of all types make work easier by changing the size or direction of an applied force. The amount of force when using simple or complex machines is called mechanical advantage.

  10. Compound Machine • This compound machine also uses pulley’s. This machine also uses a wheel and axle.

  11. Compound Machines • For the lighters, the lighters are a compound machines because it has two wheels, and a lever. The wheel is the one that helps the stone to scratch with each other and make a hot air. The lever is the one that makes the gas came out by pressing one side of it.

  12. Compound Machines • The scissors are the compound machines because it have two types of the simple machine which is the wedge, and the lever. The scissor cuts the paper with the parts of the scissor which is sharp and which acts like a wedge.

  13. Bibliography • http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm • http://www.edinformatics.com/math_science/simple_machines/wheel_and_axle.htm • http://images.google.com/images?hl=en&safe=active&um=1&q=wheel+and+axle • http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/machines.htm • http://en.wikipedia.org/wiki/Wheel_and_axle

  14. Incline Justin Eisenhauer

  15. Definition • An incline reduces the force necessary to move a load a certain distance up by providing a path for the load to move at a low angle to the ground. This lessens the needed force but increases the distance involved, so that the amount of work stays the same.

  16. Incline Mechanical Advantage • To find the mechanical advantage of using an incline you use F=wh divided by L • W stands for weight. • H stands for height. • L stands for length.

  17. How the Incline Works • The incline spreads the amount of work you have to do to raise something over a longer distance. You do not need as much force to move the object but you have to push it over a longer distance.

  18. Incline Example • A construction worker needs to move a 500 N wheelbarrow up 2 meters. He uses a 3 meter ramp. What is the mechanical advantage? • F=wh divided by h • F=500N(2) divided by 3 • F=333N

  19. Compound Machine • Bicycle • Uses wheel and axle, incline, lever, pulley

  20. Compound Machine • Slide • Uses inclines and screws

  21. Compound Machine • Scissors • Uses screw, wedge, and incline

  22. Bibliography • http://www.edinformatics.com/math_science/simple_machines/inclined_plane.htm • http://hyperphysics.phy-astr.gsu.edu/HBASE/Mechanics/incline.html • http://www.roymech.co.uk/Useful_Tables/Mechanics/Machines.html • http://physics.csustan.edu/Marvin/HowThingsWork/Machines/simple_machines.htm • http://library.thinkquest.org/CR0210120/Compound%20machine.html

  23. Screw A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw. A screw can convert a rotational force (torque) to a linear force and vice versa. Alicia Gilbert

  24. The mechanical advantage of a screw can be found by dividing the circumference of the screw by the pitch of the screw. circumference pitch IMA= The pitch of a screw is the vertical distance between two adjacent threads

  25. A screw with a diameter of 1 in. and a pitch of 10 threads per in. Circumference = 3.14xdiameter = 3.14x1= 3.14 3.14 10 = .314

  26. Force A screw reduces the force you put out because it changes torque into linear force with a screw driver, so you work less to screw something together

  27. Bicycle • Screws are used to hold the pieces together. • The wheel is a wheel and axle. • The gear shifts and brake handles are levers.

  28. Car Jack • The handle to turn is a lever • The screw that raises the jack is an inclined plane, and screws hold it together

  29. Drill • There is a wheel and axle, as well as a gear. • The drill bit is a screw

  30. bibliography • http://hyperphysics.phy-astr.gsu.edu/HBASE/Mechanics/incline.html • www.edheads.org/activities/simple-machines • www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/machines.htm • www.mikids.com/Smachines.htm • www.coe.uh.edu/archive/science/science_lessons/scienceles1/screw.htm

  31. Simple Machine: Wedge Danielle Elliott Period 3

  32. What is a wedge? • One of the six simple machines, the wedge is a triangular shaped tool, a compound and portable incline plane • It can be used to separate two objects, lift an object, or hold an object in place

  33. Mechanical Advantage • To find the mechanical advantage, divide it’s length by it’s weight. • M=L/W • The more acute the angle of the wedge, the more mechanical advantage it will yield

  34. Example: • Length=10 Width=4 • M=L/W • M=10/4= 10/4, or 2 and 1/2

  35. Compound Machine #1 -Wedge -Lever

  36. Compound Machine #2 • Wedge • Lever

  37. Compound Machine #3 • Wedge • Lever • Gear • Wheel and axel

  38. Bibliography • http://en.wikipedia.org/wiki/Simple_machine • http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm • http://www.edheads.org/activities/simple-machines/ • http://www.weirdrichard.com/wedge.htm • http://library.thinkquest.org/J002079F/wedge.htm

  39. LEVER

  40. DEFINTION A simple machine consisting of a rigid bar pivoted on a fixed point and used to transmit force, as in raising or moving a weight at one end by pushing down on the other.

  41. The mechanical advantage of a lever may also be found by dividing the length of effort arm A by the length of resistance arm a. (MA = A/a) MA = length of effort arm length of resistance arm

  42. FORCE A lever is a simple machine that consists of a rigid bar supported at one point, known as the fulcrum. A force called the effort force is applied at one point on the lever in order to move an object, known as the resistance force, located at some other point on the lever. A common example of the lever is the crow bar used to move a heavy object such as a rock. To use the crow bar, one end is placed under the bar, which is supported at some point (the fulcrum) close to the rock. A person then applies a force at the opposite end of the crow bar to lift the rock. A lever of the type described here is a first-class lever because the fulcrum is placed between the applied force (the effort force) and the object to be moved (the resistance force).

  43. Compound Machine #1 • WHEEL BARREL • Made Up Of: • A LEVER – the handles of the wheel barrel. • A Inclined Plane - the bucket of the wheel barrel. • A Wheel And Axel - the wheel and axel of the wheel barrel.

  44. Compound Machine #2 • Can Opener A LEVER – the arms on the can opener form two levers • Gear – uses energy from the turning handle to spin • Wedge – as a can opener turns the can, the wedge cuts through the metal top • Wheel and Axel – when the handle turns energy transfers to the gear and wedge which rotate and opens a can

  45. Compound Machine #3 • Stapler • A LEVER – the top arm of the stapler when you push down on this lever it transfers energy into a staple, which staples your papers. • A wedge – the staples in the staple are wedges

  46. Bibliography • http://edheads.org/b • http://www.enchantedlearning.com/physics/machines/Levers.shtml • http://www.cosi.org/files/Flash/simpMach/sm1.swf • http://www.miniscience.com/projects/pulley/ • http://library.thinkquest.org/27948/lever.html http://science.jrank.org/pages/4053/Machines-Simple-Levers.html

  47. Pulley By Kelsey Finchen

  48. Pulley • A pulley is a wheel and axle with a rope or chain attached to change the direction of a pull to lift a load.

More Related