Measuring Pressure. What does zero pressure look like? There is no force applied to an area If atmospheric pressure, there are no particles pushing on.

Slides:



Advertisements
Similar presentations
Pressure in fluids.
Advertisements

Liquid and Atmospheric
1 Chapter 6 The States of Matter 6.6 The Gas Laws.
Physics 2 Chapter 9 Section 2.
Lec 4: Fluid statics, buoyancy and stability, pressure
Fluid Statics.
Physics 101: Lecture 23, Pg 1 Physics 101: Lecture 23 Fluids: Gases and Liquids l Today’s lecture will cover Textbook Sections è Density è Pressure.
Physics 102 Part II Thermal Physics Moza M. Al-Rabban Professor of Physics Fluids.
Hydrostatics Fluids at Rest.
Pressure Measurement Muhajir Ab. Rahim
Existence of Gas pressure based on the kinetic theory gas molecules move freely and randomly. The gas molecules collide with one another and also collide.
Chapter 12: Forces and Fluids
SPH4C – Unit #4 Hydraulic and Pneumatic Systems
 How do air pressure and temperature vary in the atmosphere? Big Idea.
Measuring Pressure. Atmospheric Pressure Recall: Caused by the weight of the air molecules above us. Typically kPa or Pa Measured using.
Pgs  Calculate the pressure exerted by a fluid.  Explain Pascal’s Principle.  Calculate how pressure varies with depth in a fluid.
Measuring Pressure: Student Success Criteria I can conduct an investigation to identify factors that affect the static pressure head in fluids, compare.
Manometers and Barometers
PRESSURE OF A FLUID Barometer air pressure pressure = height of mercury column.
Monday, Nov. 22, 2004PHYS , Fall 2004 Dr. Jaehoon Yu 1 1.Density and Specific Gravity 2.Fluid and Pressure 3.Absolute and Relative Pressure 4.Pascal’s.
CHAPTER 15 : FLUID MECHANICS
CHAPTER 5: PRESSURE 5.1 Pressure and Its Units
Static Fluids.
Pressure; Pascal’s Principle
Physics 221 Department of Physics The Citadel Lecture Notes S. Yost November 17, 2008 Hydrostatics: Pressure and Pascal’s Law.
Fluids.
Wednesday, Nov. 28, 2007 PHYS , Fall 2007 Dr. Jaehoon Yu 1 PHYS 1443 – Section 002 Lecture #23 Wednesday, Nov. 28, 2007 Dr. Jae Yu Density and.
Pressure and Fluids § 12.1–12.3. Density Relating “how big” to “how much” § 12.1.
Introduction to Fluid Mechanics Engineering 1h Prof Bill Easson.
Monday, Nov. 17, 2003PHYS , Fall 2003 Dr. Jaehoon Yu 1 PHYS 1443 – Section 003 Lecture #20 Monday, Nov. 17, 2003 Dr. Jaehoon Yu 1.Density and Specific.
Fluid Statics Why do your ears hurt when you dive deep into a pool, and how can steel float on water?
Chapter 12 Outline Fluid Mechanics Density Pressure Gauge pressure Pascal’s law Buoyancy Archimedes’ principle.
Water Pressure. Also called hydrostatic pressure. Defined as the pressure exerted by a static fluid dependent on the depth of the fluid, the density of.
Air Pressure ▪The atmosphere is a blanket of gases around the planet. ▪Pressure = a force pushing on an object. ▪Air Pressure = the force of all the air.
Introducing Fluids Hydrostatic Pressure. Fluids Fluids are substances that can flow, such as liquids and gases, and even a few solids. In Physics B, we.
Fluids & Pressure Objectives:
Chapter 12 Gases Gases, Liquids and Soils Liquids and Gases Similarities: Both do not have an absolute shape Both are “fluids” because it can flow.
Hydrostatic Pressure Contents: How to calculate Whiteboards.
Pressure and Fluids § 15.1–15.5. Density Relating “how big” to “how much” § 15.1.
: a substance that has the capacity to flow and assume the form of the container it has been placed in. Fluid: a substance that has the capacity to flow.
Measuring Pressure SPH4C. Static Pressure Head For any point in a static fluid, the height of the column above that point is called the static pressure.
Weather and Climate Chapter 1 Section 2. OBJECTIVE: Investigate the properties of air.
Pressure in solids, liquids Atmospheric pressure
2/1/16Oregon State University PH 212, Class #131 Tools that Use Effects of Static Fluid Pressure Archimedes’ Principle: ・ All flotation devices Pressure.
PROPERTY OF PRESSURE z (m) Pressure the same in all directions P=  gz Pressure always perpendicular to a surface. A B Pressure the same at A and B.
PHYSICS – Pressure. LEARNING OBJECTIVES 1.8 Pressure Core Recall and use the equation p = F / A Relate pressure to force and area, using appropriate examples.
L 13 Fluids [2]: Fluid Statics  fluids at rest  More on fluids at rest  How is atmospheric pressure measured?  Buoyancy: How can a steel boat float?
Lecture 4. Pressure. 4.1 Pressure and it units Pressure = “the normal (perpendicular) force per unit area” Pressure at the bottom of the static (nonmoving)
Chapter 10 Fluids Pressure in Fluids Pressure is defined as the force per unit area. Pressure is a scalar; the units of pressure in the SI system.
Pressure and Fluids.  A gas sample is confined in a chamber with a piston. A small load is put on the piston. If the total weight of piston and load.
Chapter 12: Forces and Fluids
Chapter 6 Gases 6.2 Gas Pressure.
Pressure.
Do Now A raft is made of a plastic block with a density of 650 kg/m3, and its dimensions are 2.00 m × 3.00 m × 5.00 m. What is the force of buoyancy on.
What will happen – Why? When the barrier is removed, what will happen and can you explain why?
First Homework Due!. First Homework Due! Density.
Columns of fluid Density Pressure Pressure variation with depth
Fluids Liquids and Gases Chapter 11.
PHYSICS – Pressure.
Air Pressure The atmosphere is a blanket of gases around the planet.
Air Pressure The atmosphere is a blanket of gases around the planet.
Physical Science Forces in Fluids.
What would be more painful?
When you catch a deep-sea fish, why does its eyes pop-out?
Chapter 12 Section 1.
Air Pressure The atmosphere is a blanket of gases around the planet.
Fluid Pressure.
FLUIDS A fluid is any substance that flows and conforms to the boundaries of its container. A fluid could be a gas or a liquid. An ideal fluid is assumed.
Unit: Water and the Atmosphere Lesson 2: Air Pressure
1: Pressure depends on density and depth
Presentation transcript:

Measuring Pressure

What does zero pressure look like? There is no force applied to an area If atmospheric pressure, there are no particles pushing on the surface We call this a vacuum

Two types of pressure measurements 1)Gauge Pressure Assumes that atmospheric pressure is zero pressure Measures the difference between atmospheric pressure and an object with additional pressure

Calculating Gauge Pressure Gauge pressure = Absolute pressure – atmospheric pressure p g = p abs - p atm

Two types of pressure measurements 2) Absolute Pressure Assumes that zero pressure is zero pressure Measures the total pressure relative to a vacuum

Calculating Absolute Pressure Absolute pressure = Gauge pressure + atmospheric pressure p abs = p g + p atm

Absolute Pressure is zero Gauge Pressure is zero

Ex 1 – Note: p atm = 101kPa You come out in the morning and your car’s tire is flat. You read the side of the tire and it says “Maximum capacity 80kPa” a)What is the initial gauge pressure in the flat tire? b)What will the gauge read after you fill the tire? c)What is the absolute pressure in the tire before and after the tire is filled?

Instruments Barometer – Measures atmospheric pressure Aneroid barometer – Does not use a liquid

Instruments Altimeter – Measures altitude using the value of atmospheric pressure

Static Pressure Head Height of a column of fluid that produces a specific pressure

Calculating Pressure From Height of a Liquid p g = Dhg D – Density of the liquid (kg/m 3 ) Dwater = 1000kg/m 3 h – height of the liquid (m) g – Acceleration due to gravity (g = 9.81N/kg)

Ex 2: If you dive to the bottom of a swimming pool that is 10m deep a)What will be the gauge pressure be on your measuring instrument? b)What is the absolute pressure acting on you?

Hydroelectric Dam Greater the depth of a liquid, the greater the pressure Gravity pulls down the water, increasing the pressure on the bottom of the dam Thickest where pressure is greatest

‘Water seeks it’s own level’ In an open container, all water will settle at the same level

Work Pg 235 # 21, 23 Pg 236 # 3,7,10,11, 14 Pg 244 # 5-7,9,10