To obtain the force needed to lift a weight in a pulley system, you

To obtain the force needed to lift a weight in a pulley system, you

• A. Divide the weight by the number of sections of rope supporting the weight
• B. Multiply the weight by the number of rope sections supporting the weight
• C. Subtract weight from rope length
• D. Add weight to atmospheric pressure

Answer: (A)

In a pulley system with ideal, frictionless pulleys, the load is shared among the rope segments that support it. The force you must apply equals the weight divided by the number of supporting rope sections. This is mechanical advantage: more rope sections supporting the weight mean less input force needed. For example, if four rope sections support the weight, you only need about one-quarter of the weight as your pulling force (neglecting friction). Conversely, multiplying by the number of sections would require more force, and rope length or atmospheric pressure don’t determine the lifting force in this context.

In a pulley system with ideal, frictionless pulleys, the load is shared among the rope segments that support it. The force you must apply equals the weight divided by the number of supporting rope sections. This is mechanical advantage: more rope sections supporting the weight mean less input force needed.

For example, if four rope sections support the weight, you only need about one-quarter of the weight as your pulling force (neglecting friction). Conversely, multiplying by the number of sections would require more force, and rope length or atmospheric pressure don’t determine the lifting force in this context.