If a pulley system with an actual mechanical advantage of 2,000,000 is used in lifting a 2,000 lb. car, what effort would be needed to move the car?

0.001 lb

Explanation:

The mechanical advantage of a pulley system is given by:

where FL is the load while FE is the effort.

In this problem, we know the mechanical advantage, MA=2,000,000, and we know the value of the load, FL=2,000 lb, so we can re-arrange the equation to find the effort:

need to see circuit to get time constant

double the distance = divide strength by 4