Question

Guess and write why do tools meant for cutting always have sharp edges

Answer 1

To be able to answer this question, first, we have to know about some basic concepts of force and pressure.

By definition, pressure is "the net force applied perpendicularly on unit area". The formula for pressure is, $P=\frac{F_p}{A}$

Where  P = Pressure

             $F_p$ = net perpendicular force applied on unit area

             A = Area

So we can see that pressure is inversely proportional to area. if the applied force by a blunt edge and a sharp edge is the same, the amount of pressure will be solely dependent on the area. in this case, the blunt edge will have more area thus less pressure and the sharp edge consists much smaller area hence resulting in more pressure created than the blunt edge. Thus, tools meant for cutting always have sharp edges as they can apply more pressure. So, even with less force, more pressure can be applied to the object. Thus it can be cut easily and quickly.