The document explains the concept of pressure, including its formula and units of measurement, such as pascals (Pa). It discusses fluid pressure, stating that it varies with depth and density of the fluid, and introduces the formula for calculating pressure on submerged objects. Additionally, it includes an assignment related to Archimedes' principle, requiring a definition and example.

1. PRESSURE Objectives
:

2. PRESSURE
Pressure is the force
per unit area over
which the force is
applied.

3. Pressure
formula
• The pressure formula allows
you to calculate the pressure,
force or area given two of the
factors.
• Pressure is measured in Pascals (Pa).
1 Pascal = 1 N/m2
• Force is measured in Newtons (N).
• Area is measured in metres squared
(m2).
EXAMPLE
A force of 10N acts over an
area of 2 m2. What pressure is
created by the force?
Pressure = Force ÷ Area
Pressure = 10 N ÷ 2 m2
Pressure = 5 N m2 ---> 5 Pa

4. EXAMPLE 2
A) If a block weighs 60 N and is lying on a side with area 2m by 3m, what
is the pressure exerted on the surface?
Pressure = Force ÷ Area
P = 60 N ÷ (2m x 3m)
P = 60 N ÷ (6m2)
P = 10 Pascals
B) If the same 60 N block is now lying on its end which is 2m x 0.5m, what
is the pressure?
Pressure = Force ÷ Area
P = 60 N ÷ (2m x 0.5m)
P = 60 N ÷ (1m2)
P = 60 Pascals

5. Pressure:
Question 1

6. Pressure in Fluids
• Fluid pressure is a measurement
of the force per unit area on a
object in the fluid or on the surface
of a closed container.
• Since a fluid has no definite shape,
its pressure applies in all
directions.

7. Pressure in Fluids
• The deeper the object is placed in the
fluid, the more pressure it experiences.
• This is because is the weight of the fluid
above it.
• The more dense the fluid above it, the
more pressure is exerted on the object
that is submerged, due to the weight of
the fluid.
• The formula that gives the P pressure on
an object submerged in a fluid is
P = ρ × g × h
• ρ is the density of the fluid
• g is the acceleration of gravity
• h is the height of the object at that point in the flu

8. Density of a Fluid
• The density, (often represented by the
symbol ρ)
• is defined as the mass over the
volume.
• The unit for density is kg/m3

9. RECAP Assignment
• Do some research on
Archimedes' Principle.
This must include:
• (i) Definition of Archimedes'
Principle must be easy to
read and understand. (2
marks)
• (ii) Give an example of the
Archimedes' Principle in
effect. (3 marks)
• Here are some good
websites:
• Khan Academy
• Hyperphysics
• The Physics Classroom

10. Pressure