Which factor increases the mechanical advantage of a pulley system?

The mechanical advantage of a pulley system increases when the number of supporting strands is greater. Each supporting strand distributes the weight of the load, which means that the force required to lift the load is reduced. Essentially, the more strands there are supporting the load, the easier it becomes to lift it, as each strand takes on a portion of the load's weight. Therefore, when you increase the number of supporting strands, you effectively lower the amount of effort needed, enhancing the system's mechanical advantage.

Increasing the weight being lifted would not increase mechanical advantage; instead, it would require more force to lift that weight. Reducing the number of strands would decrease mechanical advantage, as there would be less support for the load. Using a longer length of rope could change the way force is applied but does not inherently increase the mechanical advantage; in fact, it might lead to more friction and inefficiencies in the system. Thus, increasing the number of supporting strands is the best way to enhance mechanical advantage in a pulley system.