What is meant by focal length of lens

Why does the input force have to be greater than the force needed to lift the bale?

In the sport of parasailing, a person is attached to a rope being pulled by a boat while hanging from a parachute-like sail. a rider is towed at a constant speed by a rope that is at an angle of 15 ∘ from horizontal. the tension in the rope is 1900 n. the force of the sail on the rider is 30∘ from horizontal. what is the weight of the rider? express your answer with the appropriate units.

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is