Scissors are a lever tool. The position of the handle is unchanged, and the position of the leading edge bears different stress points. The closer to the tip, the smaller the force, so the thinner the rope that can be cut.

On the contrary, the closer to the center point, that is, the position of the fulcrum of the cutting edge, the greater the force, so that there will be enough power to cut off the thick rope.

Extended data scissors use lever principle;

When using a lever, in order to save labor, a lever with a power arm longer than a resistance arm should be used; If you want to save distance, you should use a lever with a force arm shorter than a resistance arm. Therefore, the use of levers can save manpower and distance. However, if you want to save energy, you must move more distance; If you want to move a shorter distance, you must work harder. It is impossible to save energy and move the distance.

It is from these axioms that Archimedes discovered the lever principle on the basis of the "center of gravity" theory, that is, "when two heavy objects are in equilibrium, their distance from the fulcrum is inversely proportional to their weight. Archimedes' research on lever not only stays in theory, but also makes a series of inventions according to this principle.