Question

A sharp knife cuts better than a blunt knife. Which of the following option/options explain this?

• A. Blunt knife has a greater surface area in comparison to the sharp knife.
• B. Sharp knives are usually made of silver which has more strength.
• C. A sharp knife applies more pressure by virtue of its smaller contact surface.
• D. A sharp knife has more surface area and hence applies more pressure.

Answer 1

Answer: (A), (C)

The correct options are
A

Blunt knife has a greater surface area in comparison to the sharp knife.

C

A sharp knife applies more pressure by virtue of its smaller contact surface.

We know that, pressure is defined as the force acting per unit area. A sharp knife has lesser surface area than a blunt one. So, a sharp knife applies a greater pressure when used for cutting. This is why it cuts better. A blunt knife, on the other hand, has greater surface area and hence applies less pressure.