What Is Pressure?

The amount of force that presses on a certain area is known as pressure. The pressure on the surface will increase if you make the force on an area bigger. Making the area smaller and keeping the force the same also increase the pressure.

Question: You can push a drawing pin into a piece of wood- but you cannot push your finger into the wood even if you exert a larger force. Why? What is the difference between a sharp knife and a blunt knife?

Answer: The difference in each case is a difference of area- the point of the drawing pin and the edge of the sharp knife have a small area. A force acting over a small area gives a large pressure. Pressure is force per unit area, or pressure= force (in newtons)/ area (in square metres). Its unitis newtons per square metre(N/m²). The unit is also called the Pascal (Pa), named after Blaise Pascal, who investigated air pressure.