Question

Why is the cutting edge of the scissor made longer than the cutting edge of a mettal

Answer 1

Scissor and metal cutting shear are class-I lever.

For scissor, small movement at effort(at handle) should make long movement of load arm , so that it can cut longer lengths of cloth/paper. Hence blades are longer than handle.

But in metal cutting shear, we need large mechanical advantage to overcome the resistive load while cutting metal sheets. Hence its handle(load arm) is made longer than its blades.