The biggest rookie mistake? Forgetting that tension is a pulling force only. Ropes can’t push. You can’t tension a string to shove something away—that’s called a “stick.” Also, don’t ignore weight. A rope holding a sign has to fight gravity, not just your pulling. Gravity always shows up to the party.
Another classic blunder: assuming tension is the same on both ends of a pulley system. Nope! If one side has a heavier object, the tension is different on each side. It’s like a seesaw where one friend brings a sandbag. The math gets spicy, but that’s why we have equations at every pulley.
