Question

Fig. 3.1 shows a house brick of dimensions 21.0 cm x 10.0 cm x 7.00 cm.

21.0 cm
10.0 cm
7.00 cm
Fig. 3.1
The brick is held under water with its largest surfaces horizontal. The density of water is 1000 kg/m3
(a) Calculate the difference in pressure between the top and the bottom surfaces of the brick.
pressure difference

Answer 1

Given:

Lenght = 21 cm

Width = 10 cm

Height = 7 cm

Density = 1000 kg/m^3

Gravity = 9.8 m/s^2

Apply the formula:

Pressure = depth x density x gravity

Depth = Height = 7 cm = 0.07 m

Replacing:

P = 0.07 x 1000 x 9.8 = 686 Pa