Q1
What is the formula for fluid pressure?
AP = h × ρ × g
BP = h + ρ + g
CP = h ÷ ρ ÷ g
DP = h × ρ ÷ g
ICSEClass 9 (ICSE)PhysicsCh 4 · Topic 1
Pressure in Fluids and Atmospheric Pressure
Pressure in fluids acts equally in all directions and increases with depth, while atmospheric pressure is the force exerted by air on object
Core concept
Pressure in a fluid at rest is given by P = h×ρ×g, where h is depth, ρ is fluid density, and g is gravitational acceleration.
How it works
Pascal's Law states that pressure applied to an enclosed fluid is transmitted equally in all directions, used in hydraulic systems.
Why it matters
Atmospheric pressure, caused by the weight of air above us, decreases with altitude since there's less air pressing down at higher elevations.
Key detail
Understanding fluid and atmospheric pressure explains phenomena like why we can drink through a straw or why our ears pop at high altitude.
Exam highlight
Key diagram
Keywords worth remembering
Trending
pressure in fluids and atmospheric pressureicse class 9
Most searched
ICSE class 9 pressure in fluids and atmospheric pressure
Quick revision
Study resources
Notes & downloads
Quick notes
• Fluid pressure: P = h × ρ × g.
• h=depth, ρ=density, g=gravitational acceleration.
• Pascal's Law: pressure transmits equally in enclosed fluids.
• This is used in hydraulic systems.
• Atmospheric pressure is air's weight pressing down.
• It decreases with altitude.
• This explains drinking through a straw.
• It also explains ears popping at altitude.