How is ideal effort calculated using a block-and-tackle system?

In a block-and-tackle system, the concept of ideal effort is critical for understanding mechanical advantage. Ideal effort is the theoretical force required to lift a load, taking into account the number of rope strands that support the load. The formula for calculating ideal effort demonstrates that as you increase the number of strands, the effort required to lift the load decreases.

When calculating ideal effort, you divide the load (the weight being lifted) by the number of strands that are actively supporting it. This division signifies that with each additional strand, the load is distributed across more ropes, thereby reducing the amount of force needed to lift it. Thus, if you have a load of a certain weight and multiple strands enabling you to lift that weight, the ideal effort reflects this mechanical advantage by showing how many strands are participating in supporting the load.

The other options do not appropriately represent how effort is calculated in this case. Simply adding or subtracting the number of strands or multiplying them by the load does not accurately reflect the mechanical principles at play in a block-and-tackle system.