Liquid pressure

1. Liquid
Pressure

2. Introductory
Activity

3. • Does liquid exert pressure?
• If so, towards which direction does liquid exerts
more pressure ?

4. The thrust acting per unit area by a
liquid is liquid pressure. Liquid exerts
force on all sides of the container in
which they are taken

5. Developmental
activity
• How Does Liquid Pressure change with increase in
height of the liquid column?

6. The pressure exerted by a liquid column
increases with increase in Height

7. • Why is the expansion of
the balloons different ?

8. • Liquid pressure is directly proportional to
the weight of liquid column over unit area.
That is, it depends on the height of liquid
column and density of the liquid.
• If the height of the liquid column is ‘h’,
density of the liquid is ‘d’ and acceleration
due to gravity is ‘g’, then liquid pressure
P=hdg

9. Question
A water tank of height 4cm is completely filled with
water
a) Find the pressure at the bottom of the water tank
b) If the water level comes to half, what will be the
pressure at the bottom of the tank.
(Acceleration due to gravity, g=10m/s2, d=1000 kg/m3)

10. Solution
A water tank of height 4cm is completely filled with
water
a) P=hdg
= 4*1000*10
= 40,000Pa
b) P=hdg, h=2m
=2*1000*10
=20,000Pa

11. Application of Liquid Pressure in real life scenario

12. Review
Questions
• What is liquid pressure? Which are the factors
affecting it ?
• Give the equation to calculate liquid pressure

13. Follow Up
Activity
Find reason for the following and prepare a short note.
• Submarines are built using stronger materials and with
thicker walls
• Bubbles becomes larger as they rise towards the surface of
water
• Bubbles formed in water is smaller than bubbles formed in
kerosine.