Question

A brick 25cm long ,9cm wide 5cm thick has a mass of 1000g determine the greatest pressure that can be exerted by the brick on a flat surface

​

Answer 1

The greatest pressure is 2178 Pa

Step-by-step explanation:

Pressure

It's the force applied perpendicular to the surface of an object per unit area over which the force is distributed.

If F is the force applied and A is the surface area, the pressure is calculated as:

`\displaystyle P=(F)/(A)`

The brick has dimensions of 25 cm by 9 cm by 5 cm. There are three possible areas of contact:

`A_1=25*9 = 225 cm^2=0.0225\ m^2`

`A_2=25*5= 125 cm^2=0.0125\ m^2`

`A_3=9*5= 45 cm^2=0.0045\ m^2`

The brick has a mass of m=1000 g = 1 Kg and exerts a force equal to its weight when placed on a flat surface, thus:

F = m.g = 1 * 9.8 = 9.8 N

The greatest possible pressure will occur when the area is the least possible
`(0.0045\ m^2)`, since the pressure and the area are inversely proportional, thus:

`\displaystyle P_(max)=(9.8)/(0.0045)`

`\displaystyle P_(max)=2178 \ Pa`

The greatest pressure is 2178 Pa