The objective of this experiment was to study different pulley systems and determine their actual and Theoretical Mechanical Advantages and there efficiency. This was accomplished by setting up various pulley arrangements on a stable platform these systems consisted of 3 and 4 pulleys in a block and tackle like fashion. The loads the pulleys were tested with, weighed in the range 250 -500 grams and an effort required to balance these loads was determined through experimentation. These Results were plotted and it was determined that the 3 pulley system had a Actual Mechanical Advantage (AMA) of 2.5 this was in correlation to the Theoretical Mechanical Advantage (TMA) of (3.0 ), showing that the 3 pulley system had an efficiency of 84 %. The second pulley had an AMA of (3.7) and a TMA of (4.0) this produced an efficiency of 91%. From these results It can be determined that there is a force of friction acting on the pulley system and Mechanical advantage can only be used as a estimate for determining the force needed. Ways to improve the estimate include making the pulleys as small as possible and to eliminate friction by lubricating all possible surfaces.…