Physics - W.E.P. Question with Solution | TestHub

Of course you all know about pulleys, but have you really thought about utility of a pulley. The most important use of a pulley lies in the fact that a pulley not only can change direction of your effort (force), but can also make you lift a bigger weight with a smaller force. Let us consider figure 1 & 2. In both cases we have to just lift the block of mass M.

It is obvious that in case (2), $F_{effort}$ will be half of $F_{effort}$ in case (1) if we neglect mass of pulley and rope. This ability of pulley to lift greater weight by applying smaller force can be measured by quantity called Mechanical Advantage:

$$M.A=\frac{\text{Weight of the load to be lifted}}{\text{Applied force to just lift the given load}}$$

So M.A. in figure (1) is 1 and in figure (2) is 2.