why do most right-hand scissors not work when used with the left hand?

Question

why do most right-hand scissors not work when used with the left hand?

In: Physics

Answer 1

The thumb doesn’t move perfectly straight up and down, it moves in an arc because it stays the same length. This means it tends to press outward on the handle of scissors which presses the blades of the scissors together when used with the hand they were designed for.

Using the other hand (such as the left with right handed scissors) will tend to push the blades apart, offsetting the sheer force and letting the material trying to be cut to just bend and slide between the blades. That greatly reduces their effectiveness.