The direction of the force is downward Each pulley of the pulley block weighs 40n. Regardless of the rope weight and shaft friction, Xiaoming increases the 600N weight by 1m at a uniform speed. How much work does he do?

The direction of the force is downward Each pulley of the pulley block weighs 40n. Regardless of the rope weight and shaft friction, Xiaoming increases the 600N weight by 1m at a uniform speed. How much work does he do?

There is also a movable pulley for lifting the weight, that is, g = 600N + 40n = 640n
Lifting H = 1m
Substituting formula w = GH = 640j
No machine can save work, this is the principle of work. The topic proposes that other friction is not taken into account, so when calculating the total work done by people, the weight of the heavy object and the weight of the movable pulley are included. Lifting the heavy object is useful work, and lifting the movable pulley is extra work. The two can be added together