Question

Pressure at the bottom of a lake of 10 m depth is-
1. 98100 Pa
2. 98100 kPa
3. 9810 Pa
4. 9.81 kPa

Answer 1

Correct Answer - Option 1 : 98100 Pa

Concept:

Atmospheric pressure: The force per unit area pushed on any surface by the Earth's atmosphere is called atmospheric pressure.

• Atmospheric pressure decreases with an increase in the altitude for any region.
• This is because high altitude places do not have sufficient air above them, pushing down.
• Barometers are used to measure the pressure of the atmosphere. 

The atmospheric pressure is given by:

P = ρ g h 

Where ρ = Density of the fluid/air, g = Acceleration due to gravity and h = Depth

Calculation:

Given:

h = 10 m, g = 9.81 m/s² 

We know that the density of water is, ρ = 1000 kg/m³ 

Using, P = ρ g h 

P = 1000 × 9.81 × 10 

P = 98100 Pa​ = 98.1kPa