Keshu

1. What is Pressure?

Pressure is force acting perpendicular to a surface per unit area.

F

P= ----------

A

Where:

• P = pressure (Pa)

• F = force (N)

• A = area (m²)

2. Calculating FORCE Using Pressure

From the pressure formula:

F=P×A​

Example: If pressure = 500 Pa Area = 2 m²

F=500×2=1000 N

3. SI Unit

• Pressure → Pascal (Pa)

• Force → Newton (N)

1 Pa=1 N/m²

4. Pressure in Solids

Used when objects rest on surfaces.

mg

P= ----------

A

Force due to weight:

F=mg

Where:

Where:

• M = mass

• g=9.8 m/s²

5. Pressure in Liquids (Hydrostatic Pressure)

P=ρgh​

Where:

• ρ = density

• g = gravity

• h = depth

Force due to liquid pressure:

F=P×A=ρghA

6. Total Pressure in Liquids

Ptotal=Patm+ρghP

Corresponding force:

F=Ptotal×A

7. Pressure Difference in Liquids

ΔP=ρgΔh

Force due to pressure difference:

ΔF=ΔP×A

8. Atmospheric Pressure

At sea level:

5

Patm=1.013×10 PA THE FIVE IS THE POWER OF 5

Force due to atmosphere:

F=Patm×A