Post on 21-May-2015
Home
End
HolisticTuition
CashPlants
Chapter 3: Chapter 3: Forces & PressureForces & Pressure
Form 4Form 4
1
PhysicsPhysicsNext >
The study of The study of mattermatter
Home
End
HolisticTuition
CashPlants
Objectives: Objectives: ((what you will learnwhat you will learn)) 1) understanding Pressure
2) understanding the Principles
Physics: Chapter Physics: Chapter 33
2
< Back
Next >
Home
End
HolisticTuition
CashPlants
PressurePressure
3
< Back
Next >
Pressure = force per unit area
Pressure, P
= Force, FArea, A , N m-2 or Pa
(Pascal)If a fluid (liquid or gas) has a density ρ, its pressure P, at a point due to the fluid of height h, is given byP = ρgh where g = gravitational field
strength
For a given point in the fluid, its pressure acts equally in all directions.
It does not depend on the shape of containers.
Therefore, for a given liquid, its pressure:- increases with depth- increases with density
Home
End
HolisticTuition
CashPlants
4
< Back
Next >
AtmosphereAtmosphereAtmosphere is the layer of thick air which surrounds the Earth.
The pressure exerted on the Earth’s surface by the atmosphere is the atmospheric pressure, which can be measured using Fortin barometer or Aneroid barometer.
1 atmosphere
= 760 cm Hg
= 10.3 m water
= 101,300 Pa
1 millibar = 100 Pa
Home
End
HolisticTuition
CashPlants
5
< Back
Next >
The PrinciplesThe PrinciplesPascal’s Principle:
The pressure applied to an enclosed liquid is transmitted equally to all parts of the liquid.
Archimedes’ Principle:
When an object is immersed in a fluid the buoyant force on the object is equal in size to the weight of fluid displaced by the object.
Bernoulli’s Principle:
When the velocity of a fluid increases, the pressure of the fluid decreases.
Home
End
HolisticTuition
CashPlants
6
SummarySummary
< Back
What you have learned:What you have learned:
1.1. Understanding Understanding PressurePressure
2.2. Understanding theUnderstanding the Principles Principles
Thank YouThank You