So far i've understood that a single pulley changes the direction of the force, but how does multiple pulleys decrease the amount of force needed?
For example in (a), why is the middle force arrow pointing upwards? shouldn't it point down since the pulley only changes the direction of the force. It makes sense on the right most force arrow since that points down so the left most force arrow points up. Since that left most force arrow points up wouldn't the middle force arrow point down?
Sorry if i'm not clear with the question, I am a bit confused about pulleys even though this is quite basic!