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Jake Bobowski
Приєднався 14 вер 2014
PHYS 301 - 20241023
PHYS 301 - 20241023
- Generating orthogonal polynomials using the Gram-Schmidt method
- Discovering that the orthogonal polynomials that we generated are the Lengendre polynomials (to within a scaling factor)
- Separation of variables in spherical coordinates with azimuthal symmetry
- Generating orthogonal polynomials using the Gram-Schmidt method
- Discovering that the orthogonal polynomials that we generated are the Lengendre polynomials (to within a scaling factor)
- Separation of variables in spherical coordinates with azimuthal symmetry
Переглядів: 17
Відео
PHYS 231 - 20241023
Переглядів 1715 годин тому
PHYS 231 - 20241023 - Op amp limitations (clipping, high-frequency roll off) - The inverting amplifier - The non-inverting amplifier
PHYS 231 - 20241021
Переглядів 187 годин тому
PHYS 231 - 20241021 - Definition of the complex conjugate z* - Using z* to find the magnitude of z - Using z* to remove j's from the denominator of a complex ratio - Introduction to operational amplifiers (op amps) - Negative feedback and the two op amp Golden Rules
PHYS 231 - 20241016
Переглядів 2219 годин тому
PHYS 231 - 20241016 - Completing the analysis of a series LRC circuit in the frequency domain. - Plot of VR/V0, where VR is the amplitude of the voltage across the resistor and V0 is the amplitude of the signal generated by the signal generator - Plot of the phase of VR versus frequency - Resonance frequency and the width of the resonance - More on interpreting complex quantities and complex al...
PHYS 301 - 20241016
Переглядів 3119 годин тому
PHYS 301 - 20241016 - Completing separation of variables example in Cartesian coordinates (finding Fourier coefficients to fit boundary conditions). - A deep dive into Legendre polynomials. - Vectorizing functions - The inner product of functions (analogy with dot products of vectors) - Orthogonal basis functions - Expansion of f(x) in terms of projections onto the basis functions
PHYS 301 - 20241009
Переглядів 1314 днів тому
PHYS 301 - 20241009 Finding potentials in a charge-free region of space. - The method of images - Solving Laplace's equation by separation of variables
PHYS 231 - 20241009
Переглядів 9314 днів тому
PHYS 231 - 20241009 Using complex numbers to solve for the current in AC circuits with resistors, capacitors and inductors. - Series LRC circuit - Impedance of capacitors and inductors - Magnitude and phase of the current - Complex algebra
PHYS 301 - 20241007
Переглядів 3414 днів тому
PHYS 301 - 20241007 - Properties of the solutions to Laplace's equation in 1-D, 2-D, and 3-D - Two uniqueness theorems
PHYS 231 - 20241007
Переглядів 4214 днів тому
PHYS 231 - 20241007 - The complex plane and two ways to express complex numbers. - Review of the Maclaurin series expansion - Euler's equation
PHYS 231 - 20241002
Переглядів 4421 день тому
PHYS 231 - 20241002 - Analysis of the frequency dependence of an RC circuit (high-pass filter) - Introduction to complex numbers
PHYS 301 - 20241002
Переглядів 4121 день тому
PHYS 301 - 20241002 Jake Bobowski - UBC Okanagan - Energy of charge distributions - Conductors in electrostatic equilibrium - Electrostatic pressure
PHYS 231 - 20240925
Переглядів 7628 днів тому
PHYS 231 - 20240925 Jake Bobowski - UBC Okanagan - Measuring the time constant of a series RC circuit - The transient response of a series LRC circuit - Analysis of the frequency response of a series LRC circuit
PHYS 301 - 20240925
Переглядів 6128 днів тому
PHYS 301 - 20240925 Jake Bobowski - UBC Okanagan - The electric potential (point charges and continuous charge distributions) - Poisson's equation and Laplace's equation - Boundary conditions on the electric field across the charged surface
PHYS 231 - 20240923
Переглядів 22Місяць тому
PHYS 231 - 20240923 - Propagation of errors examples - "Derivation" of the standard error in the mean - Preview of Lab #3
PHYS 301 - 20240923
Переглядів 55Місяць тому
PHYS 301 - 20240923 Jake Bobowski - UBC Okanagan - Gauss's law (integral and differential forms) - Application of Gauss's law to find electric fields - The curl of E
Thank you!
Balls
critical damping is not the fastest in reaching equilibrium state...especially not in a practical sense (i.e. in experiments and applications)...e.g. damping coefficient about 10% smaller than critical can be a much better choice, and sometimes (depending on the initial conditions) even a damping coeffficient in the overdamp regime can be the fastest in reaching equilibrium state...there are some subtleties to this issue that are often not considered...
18:11 If I point my right thumb down in the direction of the induced field, the current flows the opposite way to the diagram, doesn't it?
Yes, you're right! Good catch. Thanks for pointing out my mistake.
So what's the power output?
The work done per cycle is determined by the area of the loop in the PV-diagram. Roughly speaking, with no friction applied to the flywheel, the change in volume is about 0.5 cm^3 and the change in pressure is about 1.2 kPa. Therefore, the area/work is approximately W = 0.6 mJ. In reality, the work is a little less because the PV-diagram is not rectangular. The power output is given my P = W/T, where T is the period of cycle. Without friction, the period is approximately T = 0.2 s such that the power output is about 3 mW = 4 micro-horsepower! When friction is applied, the work per cycle increases and the power output decreases. The power decreases because the period of the cycle increases more than the work per cycle.
How watch like these vidos?
28.02 class starts from here
Am i understanding correctly that the volume of the engine is calculated externally? looked like you were using a sensor to add value of the volume depending on flywheel positioning.
you explained it in the part of the video i skipped over, sorry
Alles good experiment!
Pipe internal diameter and ball?
It's in the description.
Impressive but why 100 trials ? uncertainty ?
Yes, the uncertainty in the measured period decreases as one over the square root of the number of trials.
Is it correct to assume zero pressure on the graph represents atmospheric pressure, therefore when a negative (below 0) pressure is indicated that would represent an internal working fluid pressure lower than the outside atmospheric pressure?
Yes, that is correct. The pressure sensor measures the difference between the pressure outside the engine (atmospheric pressure) and the pressure of the gas inside the engine, which can be greater than or less than atmospheric pressure.
@@jakebobowski3165 Thank you. Is there any possible way to also take temperature readings? It is difficult to understand how, in an enclosed heated space containing an expanding hot gas, the internal pressure can drop below the outside atmospheric pressure, unless there is a concomitant drop in temperature. But is there any thermocouple, or other instrument, with a fast enough response time to measure the actual gas temperature in real time?
@@peoplesresearchcenter6184 It's probably difficult to get a direct measurement of the gas temperature. However, you could deduce what it must be using the ideal gas law and knowledge of the instantaneous pressure and volume (PV = nRT). You would have to estimate the number of moles of gas contained inside the engine using the internal volume and the density of the air.
The diameter of the sphere ?
Closely matched to the inner diameter of the tube (given in the description). It's a close fit while still being able to slide smoothly.
nifty
Thanks for the video!
No worries! There are more related videos here: ua-cam.com/play/PLfhjdV-pwMOb7HIHkZi2OqyXWk0ulCPWu.html The videos related to statistical mechanics start at w8l3 and end at w10l1 in which low- and high-temperature approximations of the grand potential are discussed.
Cool! Are those lines/ blocks caused by rolling shutter?
You have a beautiful singing voice
Truly, a beautiful graph. 10/10, would derive period again.
Lovely 😍💋 💝💖❤️
you can hear a cat meow at 19:21
Awesome demonstration!!
WOW
Why is it that the particles in the final graphs that were the furthest distance away scattered at the steepest angles, rather than the particles that approached closest (and therefore experienced the strongest repulsive force)? Or is that just because the constants selected for m,q,l etc. were not the same?
Good question. Those plots were made by setting ml^2/(keQq)) = 1 meter for all of the curves. The only difference between each of the lines is the value of theta_0 chosen. However, the angular momentum per unit mass l is equal to v_0 times b where v_0 is the initial speed of the alpha particle and b is the impact parameter. For the red curve b is large therefore, to maintain a constant value of l, the particle's initial speed is small. For the cyan curve, the opposite is true. The impact factor is small, therefore v_0 is large. The differences in initial speed have a large effect on the shapes of the curves.
Big fan of the online lectures
Thanks! I like it too.
I really appreciate that you chose to make your lectures UA-cam videos. I find it very helpful to be able to go back through the lecture to listen to you explain a concept. Thank you for transitioning online so smoothly!
Gonna miss that left hand :(
You can hear is cat meow at 15:09
Whos here cuz of JLZ?
You are doing great at transitioning to online!
The best out of any of my professors!
Thanks for the encouraging words! I'm now a "UA-camr" out of pure necessity.