PULLEYS AND LIFTING  IMPORTANT FORMULAS
V. Ryan © 2004 2010
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When using pulleys for lifting the formulas for mechanical advantage and velocity ratio are very important. The formulas are shown below. 

FORMULAS RELATING TO MECHANICAL ADVANTAGE 

Mechanical advantage is defined as the ratio of load to effort. Pulley systems rely on this important relationship between load and effort. The formula seen below is best understood by writing it within a triangle. This helps when it is necessary to change the formula to find either; mechanical advantage or the load or the effort. In this way three formulas can be generated from the single formula inside the triangle. 



FORMULAS RELATING TO VELOCITY RATIO  
Velocity Ratio (sometimes called movement ratio) is defined as the ratio of the distance moved by the effort to the distance moved by the load. The formula seen below is best understood by writing it within a triangle. This helps when it is necessary to change the formula to find either; velocity ratio or the distance moved by the load or the distance moved by effort. In this way three formulas can be generated from the single formula inside the triangle. 

