With the help of a movable block, the load was lifted to a height of 1.5 m. How long was the free end of the rope pulled?

According to the equilibrium condition of the lever:
F1 * l1 = F2 * l2, where l1 is the height of the load (l1 = 1.5 m).
Since the movable block gives a 2-fold gain in strength and is a lever with one arm twice as large as the second, F1 = 2F2, where F2 is the force applied to the block.
Let us express and calculate the length of pulling the free end of the rope:
l2 = F1 * l1 / F2 = 2F2 * 1.5 / F2 = 3 m.
Answer: The free end of the rope was stretched 3 m.