 Lecture in Fluids

(Last Updated On: December 13, 2017)

Lesson Objectives – the students should be able to:

• Distinguish between density, weight density, and specific gravity and given an object’s mass and volume, calculate the object’s density, weight density, and specific gravity.
• Define pressure and calculate the pressure that an object of known weight exerts on a surface of known area and express the magnitude of the pressure in psi, lb/ft2, N/m2, or pascals (Pa).
• Calculate the pressure acting at a depth h below the surface of a liquid of density (ρ).
• Distinguish between absolute pressure and gauge pressure and solve problems involving each type of pressure.
• State Pascal’s Principle and apply this principle to basic hydraulic systems.
• State Archimedes Principle and use this principle to solve problems related to buoyancy.
• Explain what is meant by streamline flow, the equation of continuity, and the flow rate. Apply these concepts to word problems to solve for the velocity of water at a particular point in a closed pipe.
• Use Bernoulli’s equation and the concept of streamline flow to solve for the velocity of a fluid and/or the pressure exerted by a fluid at a particular point in a closed pipe.

Summary of Chapter 10

• Phases of matter: solid, liquid, gas.
• Liquids and gases are called fluids.
• Density is mass per unit volume.
• Specific gravity is the ratio of the density of the material to that of water.
• Pressure is force per unit area.
• Pressure at a depth h is ρgh.
• External pressure applied to a confined fluid is transmitted throughout the fluid.
• Atmospheric pressure is measured with a barometer.
• Gauge pressure is the total pressure minus the atmospheric pressure.
• An object submerged partly or wholly in a fluid is buoyed up by a force equal to the weight of the fluid it displaces.
• Fluid flow can be laminar or turbulent.
• The product of the cross-sectional area and the speed is constant for horizontal flow.
• Where the velocity of a fluid is high, the pressure is low, and vice versa.
• Viscosity is an internal frictional force within fluids.
• Liquid surfaces hold together as if under tension.

Units of Chapter 10 – Keywords

• Density and Specific GravityDensity and Specific Gravity
• Density and Specific Gravity
• Pressure in Fluids
• Atmospheric Pressure and Gauge Pressure
• Pascal’s Principle
• Measurement of Pressure; Gauges and the Barometer
• Buoyancy and Archimedes’ Principle
• Fluids in Motion; Flow Rate and the Equation of Continuity
• Bernoulli’s Equation
• Applications of Bernoulli’s Principle: from Torricelli to Airplanes, Baseballs, and TIA
• Viscosity
• Flow in Tubes: Poiseuille’s Equation, Blood Flow
• Surface Tension and Capillarity
• Pumps, and the Heart