Question

Explain the following:
a. Why can't we hammer a nail by its head on the wood?
b. A sharp knife cuts better than a blunt knife.

Answer 1

We know that pressure = $\frac{Force}{Area}$

a. The head of a nail has a larger area than its tip. So, when an equal amount of force is applied on the nail's head as well as its pointed end, it can be noticed that the pressure on the head would be lesser to cause a significant impact when compared to the other case.

b. A sharp knife has a lesser surface area than blunt one. So, a sharp knife applies a greater pressure when used for cutting.