Question

In a pulley setup that has a moving pulley, _____

A. You have to pull the string a greater distance, and it takes more work to lift the mass
B. Your work doubles because the pulley moves
C. You have to pull the string a greater distance, but the force needed to lift the mass is cut in half
D. You don't have to pull very much to lift the mass

Answer 1

the answer is d
the whole purpose of pulley system is to save work

Answer 2

D. You don't have to pull very much to lift the mass.

Step-by-step explanation:

With a moving pulley you don't have to pull very much to lift the mass, because this pulley distributes better the weight, requiring a lower force to lift than using a simple pulley.

So, basically, in this type of system, the force needed is less, however, to know if is half less or even a minor proportion, we need to use specific values, that's why option C is not the answer, because with the data given, you cannot calculate if the force needed is the half.