Basic Machines: Difference between revisions
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| [http://wiki.dtonline.org/index.php/Category:Levers '''Levers'''] are described in three ‘classes’ as determined by the relative positions of the '''load''', '''fulcrum''' and '''effort'''. Levers are often used to move heavy loads, as with the Class 1 Lever shown, but if used in reverse, as it were, and the heavy boulder becomes the applied force, then we have the basis of a [https://en.wikipedia.org/wiki/Trebuchet '''Trebuchet'''] type seige weapon making use of the amplification of movement the lever can provide. | | [http://wiki.dtonline.org/index.php/Category:Levers '''Levers'''] are described in three ‘classes’ as determined by the relative positions of the '''load''', '''fulcrum''' and '''effort'''. Levers are often used to move heavy loads, as with the Class 1 Lever shown, but if used in reverse, as it were, and the heavy boulder becomes the applied force, then we have the basis of a [https://en.wikipedia.org/wiki/Trebuchet '''Trebuchet'''] type seige weapon making use of the amplification of movement the lever can provide. | ||
The extent to which a Lever can increase effort is calculated as its '''[[Mechanical Advantage]]''' and the degree to which it amplifies movement is calculated as its '''[[Velocity Ratio]]''' | The extent to which a Lever can increase effort is calculated as its '''[[Mechanical Advantage]]''' and the degree to which it amplifies movement is calculated as its '''[[Velocity Ratio]]''' | ||
| [[File:MechanismsClass1Lever.jpg|150px]] | |||
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| [https://en.wikipedia.org/wiki/Pulley '''Pulley'''] | |||
| '''[[Pulley|Pulleys]]''' can be used speed up or slow down rotating shafts or, as in the example shown, simply to change the line of effort to a more convenient direction. | |||
| [[File:PulleyHoist.jpg |150px]] | |||
[[Category:Mechanisms]] | |||
Revision as of 16:57, 8 February 2015
Machines are mechanical devices which are designed such that available sources of energy, force or effort can be used to perform a useful task or to do work. Some Basic Machines simply enable effort to be applied in a more convenient direction, but more often they are used to increase the load that can be moved or amplify the distance travelled.
| Lever | Levers are described in three ‘classes’ as determined by the relative positions of the load, fulcrum and effort. Levers are often used to move heavy loads, as with the Class 1 Lever shown, but if used in reverse, as it were, and the heavy boulder becomes the applied force, then we have the basis of a Trebuchet type seige weapon making use of the amplification of movement the lever can provide.
The extent to which a Lever can increase effort is calculated as its Mechanical Advantage and the degree to which it amplifies movement is calculated as its Velocity Ratio |
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| Pulley | Pulleys can be used speed up or slow down rotating shafts or, as in the example shown, simply to change the line of effort to a more convenient direction. | 
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