Question

Why are the handles of a pair of scissors smaller than its blades while the handles of a pair of shears longer than the blades? Both are 1st class lever.

Answer 1

We know that scissors are used for cutting cloth and shears are used for cutting metals.
Both belong to class I levers.
For class I levers,Mechanical advantage is given by
MA=Effort arm / Load arm
It may be >,= or < 1.
For cutting cloths less mechanical advantage is required than for cutting metals. Therefore scissors may have blades much longer than the handles,On the other hand shears for cutting metals have short blades and long handles.