Question

(a) What is the ideal mechanical advantage of a single pulley?

(b) There is no gain in mechanical advantage in case of a single fixed pulley. Explain, why the pulley is then used.

Answer 1

(a)

1. A single fixed pulley has ideal mechanical advantage of 1 since the effort force is equal to the load force.
2. A single fixed real pulley has a mechanical advantage of less than one.
3. There is a change in force direction, and some work is done to overcome the friction in the pulley.
4. As a result, the force required to draw the rope from your end will be greater than the force required from the other end.

(b)

1. There is no gain in mechanical advantage in the case of a single fixed pulley.
2. A single fixed pulley is used only to change the direction of the force applied that is with its use, the effort can be applied in a more convenient direction.
3. To raise a load directly upwards is difficult.