What will be the new capacity when changing a 1:1 elevator system rated at 2000 lbs to a 2:1 system?

In a 1:1 elevator system, the capacity is determined by the ratio of the weight it can lift relative to the mechanism used. In this case, the initial system has a rated capacity of 2000 lbs.

When you switch to a 2:1 system, the configuration effectively doubles the capacity because of the way the pulley system redistributes the load. In a 2:1 system, for every unit of load in the elevator, there are two units of cable support, which means the lifting mechanism is halving the effective load that the motor must support compared to a 1:1 system. As a result, for the same motor power and mechanism, the new capacity is twice that of the original system.

Therefore, if the original capacity was 2000 lbs in a 1:1 system, transitioning to a 2:1 system increases the capacity to 4000 lbs. Thus, choosing an answer of 4000 lbs is correct, reflecting the increased lifting capability afforded by the new arrangement.