Fluids and Waves with Lab Demonstrations

Video Lectures

Displaying all 29 video lectures.
Lecture 1
Elasticity 1: Stress and Strain
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Elasticity 1: Stress and Strain
This lecture introduces the concept of elasticity and covers the definitions of different types of mechanical stress and strain.
Lecture 2
Elasticity 2: Young's Modulus
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Elasticity 2: Young's Modulus
This lecture shows how to measure Young's Modulus for an elastic band. This includes examples of how to calculate experimental uncertainties using partial derivatives which is a good introduction to their use for later in the course with waves.
Lecture 3
Elasticity 3: Moduli of Elasticity
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Elasticity 3: Moduli of Elasticity
This lecture extends the concept of Young's Modulus to the general case: Modulus of Elasticity. Moduli for the different types of stress and strain are discussed an a new type of stress, bulk stress, is introduced along with it's associated bulk strain and bulk modulus.
Lecture 4
Elasticity 4: Elastic Limits
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Elasticity 4: Elastic Limits
This lecture returns to the Young's Modulus elastic band experiment to demonstrate the effect of hysteresis when the band is unloaded. The elastic limit, plastic deformation and breaking stress are described in the context of a stress-strain plot. Finally the concepts of ductile and brittle materials are discussed.
Lecture 5
Fluid Statics 1: Pressure and Density
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Fluid Statics 1: Pressure and Density
In this lecture we introduce the concepts of pressure and density for a fluid and demonstrate how pressure acts in all directions.
Lecture 6
Fluid Statics 2: Static Pressure
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Fluid Statics 2: Static Pressure
This lecture starts with the derivation of the static pressure at depth in a fluid and the behaviour of fluids which results from that. The lecture concludes with Pascal's Law and a demonstration of how hydraulics work.
Lecture 7
Fluid Statics 3: Pressure Gauges
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Fluid Statics 3: Pressure Gauges
This lecture describes how we can use the static pressure of a liquid to convert pressure measurements into length measurements. We also see that sucking water out of a bottle has its limits!
Lecture 8
Fluid Statics 4: Buoyancy Force
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Fluid Statics 4: Buoyancy Force
In this final lecture on fluid statics we discuss the buoyancy force which an object immersed in a fluid is subject to and which was first quantified by Archimedes.
Lecture 9
Fluid Dynamics 1: Fluid Flow
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Fluid Dynamics 1: Fluid Flow
Flow is a defining characteristic of a fluid. This lecture introduces the concept of surface tension and then covers the types of of fluid flow using examples both in nature and the lab. To conclude the continuity equation is introduced and used to characterize the flow of incompressible liquid in a pipe.
Lecture 10
Fluid Dynamics 2: Bernoulli's Equation
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Fluid Dynamics 2: Bernoulli's Equation
Starting with conservation of energy for fluid flows we derive Bernoulli's equation which is then demonstrated in some fun, and counterintuitive experiments - some of which you can easily try for yourselves. To conclude Torricelli's law is also derived and demonstrated.
Lecture 11
Fluid Dynamics 3: Viscosity
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Fluid Dynamics 3: Viscosity
To conclude our discussion of fluid dynamics we introduce the concept of viscosity, starting with the definition of shear, or dynamic viscosity and its effects of fluid flow in a pipe. Viscous flow in the simplest possible situation, a long, straight circular pipe is discussed in terms of Poiseuille's law and the lecture concludes with a demonstration of this.
Lecture 12
Oscillations 1: Derivation of Simple Harmonic Motion
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Oscillations 1: Derivation of Simple Harmonic Motion
This video introduces the parameters used to describe an oscillator and, using the case of a mass-spring systems, derives the solution for the displacement of the mass as a function of time.
Lecture 13
Oscillations 2: SHM Parameters
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Oscillations 2: SHM Parameters
Here we relate the solution for the displacement with the physical parameters of simple harmonic motion and demonstrate that the solution is consistent with experiment.
Lecture 14
Oscillations 3: Phasors
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Oscillations 3: Phasors
This video demonstrates that the displacement of a simple harmonic oscillator can be written down in several, mathematical equivalent ways including a rotating vector in the complex plane called a phasor. It also shows the solution for a vertical mass-spring system.
Lecture 15
Oscillations 4: Kinematics and Energy
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Oscillations 4: Kinematics and Energy
This video shows how to derive the velocity and acceleration of a simple harmonic oscillator. We then use the velocity and displacement to calculate the kinetic and potential energy of the oscillator and show that the total is constant.
Lecture 16
Oscillations 5: Pendulums
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Oscillations 5: Pendulums
In this lecture we solve for the motion of simple and compound pendulums and demonstrate that, for small amplitudes, they undergo simple harmonic motion.
Lecture 17
Oscillations 6: Damped Oscillators
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Oscillations 6: Damped Oscillators
This lecture solves for the motion of a harmonic oscillator which has a damping force applied. The result solutions are classified into one of three types and the motion for each discussed.
Lecture 18
Oscillations 7: Driven Oscillators
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Oscillations 7: Driven Oscillators
In this video we solve for the situation where a periodic force is applied to a damped, harmonic oscillator. The resulting equation of motion is solved to determine the amplitude and phase of the oscillator's displacement.
Lecture 19
Oscillations 8: Resonance
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Oscillations 8: Resonance
Building on the solution for the amplitude of a driven harmonic oscillator we show that this leads to the phenomenon of resonance. This is demonstrated for a simple, mechanical oscillator as well as an AC circuit and at a fundamental particle level with the production of Z bosons.
Lecture 20
Waves 1: Wave Types and Properties
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Waves 1: Wave Types and Properties
Introduction to the phenomenon of waves. This lecture introduces the basic properties of waves such as frequency, wavelength and wave number and shows how these are related to the phase velocity of the wave.
Lecture 21
Waves 2: The Wave Equation
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Waves 2: The Wave Equation
Shows the derivation of the wave equation from first principles.
Lecture 22
Waves 3: Solving the Wave Equation
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Waves 3: Solving the Wave Equation
Solves the wave equation using the separation of variables technique to derive the mathematical description of a wave. It also introduces the concept of Fourier transforms to show how we can make different wave shapes from sine waves.
Lecture 23
Waves 4: Waves on a String
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Waves 4: Waves on a String
This lecture demonstrates how to derive the wave equation for waves on a string and uses it to calculate the phase velocity of this type of wave. It includes some qualitative demonstrations on how the phase velocity changes with both the mass per unit length of the string and the tension in it.
Lecture 24
Waves 5: Acoustic Waves
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Waves 5: Acoustic Waves
This lecture shows how to derive the wave equation for an acoustic wave both as a pressure wave and as a displacement wave and this is used to calculate the phase velocity. The phase difference between the displacement and pressure deviation is also calculated.
Lecture 25
Waves 6: Wave Intensity
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Waves 6: Wave Intensity
This video introduces the concept of wave intensity for 3D waves by considering the wave power of an acoustic wave. Applying conservation of energy shows how the intensity decreases with distance from the source and that the relationship is different for both surface and bulk waves and how knowing this can lead to some amazing measurements.
Lecture 26
Waves 7: Superposition
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Waves 7: Superposition
This lecture discusses what happens when two waves are super imposed on each other. Starting with a demonstration of two pulses on a string the observed behaviour is related to the wave equation. The discussion is then broadened to reflection of waves at boundaries and the general principle of superposition and phase difference is included.
Lecture 27
Waves 8: Interference
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Waves 8: Interference
In this lecture we will show what happens when waves interact from two identical sources of waves. The phenomenon of beats, from two sources of slightly different frequencies will also be demonstrated.
Lecture 28
Waves 9: Standing Waves
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Waves 9: Standing Waves
This lecture covers the important topic of standing waves which is the physics behind not only music but atoms as well. Standing waves on strings an pipes will be derived and demonstrated.
Lecture 29
Waves 10: The Doppler Effect
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Waves 10: The Doppler Effect
This video introduces the doppler effect which is cause by the motion of a wave source and observer relative to the medium of the wave. The relativistic doppler effect for EM waves will also be derived.