What is the purpose of a block-and-tackle system?

The purpose of a block-and-tackle system is to provide a mechanical advantage to lift heavy loads. This system utilizes multiple pulleys in conjunction with ropes or cables, which effectively redistribute the weight of the load being lifted. By employing this arrangement, the amount of force required to lift the load is significantly reduced, enabling operators to lift heavier weights than they could manage using direct lifting techniques alone.

This mechanical advantage comes from the reduction of effort needed; as the load is shared among several pulleys, the effort exerted by the operator is divided. This allows for safer and more efficient lifting operations, especially in industrial settings where manual lifting might be impractical or unsafe.

The other options do not fully capture the fundamental role of a block-and-tackle system. While it can help stabilize a load, that is not its primary function. Securing loads during transport or measuring weight accurately are also not objectives of a block-and-tackle system.