Question

Calculate the pressure exerted by a brick, which applies a force of 30 N, when

(a) It is placed upright on the soil.

(b) When it is placed on its widest base.

The length, breadth and height of the brick are 20cm, 10cm & 5 cm respectively ​

Answer 1

$\huge\boxed{\mathtt\red{Solution :-}}$

Given :-

• force exerted by the brick is 30N
• dimension of the brick is 20cm (length), 10cm (breadth) and 5cm (height)

To Find :-

• pressure when placed upright on the soil.
• pressure when placed on widest base.

Solving :-

(i).

⟹ Area when brick is placed upright = height×breadth

✒ Area = 5 cm × 10 cm

∴ Area = 50 cm²

Now, convert area into metres :-

⟹ 50 cm² = 0.005 m²

✰ The pressure exerted by the brick is :-

$\large\mathtt{pressure = \frac{mass}{area}}$

✒ pressure = 30 N / 0.005 m²

✒ pressure = 6000 N/m

$\large\boxed{\mathtt\green{∴ pressure = 6000 pa}}$

(ii).

⟹ area when brick is at widest base = length×breadth

✒ area = 20 cm× 10cm

∴ Area = 200 cm²

Now, convert area into metres :-

⟹ 200 cm² = 0.02 m²

✰ The pressure exerted by the brick is :-

$\large\mathtt{pressure = \frac{mass}{area}}$

✒ pressure = 30 N / 0.02 m²

✒ pressure = 1500 N/m

$\large\boxed{\mathtt\green{∴ pressure = 1500 pa}}$