Question

A block measures 20cm by 10cm by 5cm. Determine the minimum pressure the solid can exert on a flat surface if the mass is 50kg

Answer 1

Given data : A block measures 20cm by 10cm by 5cm and mass of block is 50 kg.

To find : Determine the minimum pressure the solid block can exert on a flat surface.

Solution : As per given data we know that shape of solid block is cuboid. Here we know, opposite site faces of cuboid are equal.

Let, diamension's of solid block as follows :

• Length of block = 20 cm
• Width of block = 10 cm
• Height of block = 5 cm
• Mass of block = 50 kg

Here, we know block is placed on flat surface, hence to calculate force exerted by block on flat surface we use formula of force,

⟹ Force = mass * acceleration due to gravity

⟹ Force = 50 * 9.8

⟹ Force = 490 N

We can place the solid block in 3 ways so,

Now, we use formula of pressure,

⟹ Pressure = Force/Area

⟹ Pressure = 490/(length * width)

⟹ Pressure = 490/(20 * 10)

⟹ Pressure = 490/200

⟹ Pressure = 2.45 pa ----{1}

⟹ Pressure = Force/Area

⟹ Pressure = 490/(length * height)

⟹ Pressure = 490/(20 * 5)

⟹ Pressure = 490/100

⟹ Pressure = 4.9 pa ----{2}

⟹ Pressure = Force/Area

⟹ Pressure = 490/(width * height)

⟹ Pressure = 490/(10 * 5)

⟹ Pressure = 490/50

⟹ Pressure = 9.8 pa ----{3}

Answer : Hence, from {1}, {2} and {3} maximum pressure is 9.8 pa and minimum pressure is 2.45 pa.

[ 2.45 pa < 4.9 pa < 9.8 pa]