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Dr. S Physics
United States
Приєднався 10 гру 2020
I have a PhD in physics and currently do astronomy/astrophysics/cosmology research. This channel contains interesting discussions on popular science, physics lectures, and problem solving.
Gas Laws and Phases of Matter
In this video I introduce gas laws that describe ideal gasses, with variables such as pressure, temperature, and volume, and number of particles. We end with a description of phase transitions between solid, gas, and liquid.
Переглядів: 32
Відео
Temperature
Переглядів 224 місяці тому
In this video I introduce the concept of temperature. We discuss three temperature scales, Fahrenheit, Celsius, and Kelvin, and how to convert between the two. We finish with a discussion of how temperature affects the lengths and volumes of objects.
A Brief Discussion of Waves
Переглядів 134 місяці тому
In this video I briefly discuss waves, their properties such as amplitude, wavelenghth, and frequency, constructive and desctructive interference, and the connection between waves and harmonic oscillators.
Damped and Driven Oscillators
Переглядів 344 місяці тому
In this video I introduce the formulas for damped harmonic oscillators and driven harmonic oscillators, using a mass spring system as a starting point.
Simple Harmonic Oscillators
Переглядів 324 місяці тому
In this video I introduce the concept of simple harmonic oscillators, which covers topics such as springs, pendulums, and waves. I derive the period of a pendulum as an example of how to treat harmonic motion.
Hamiltonian Mechanics
Переглядів 798 місяців тому
In this video I introduce Hamiltonian Mechanics, a parallel formalism to Lagrangian Mechanics. I show how the Lagrangian and Hamiltonian are related, and how to define the generalized momentum. I then show how to use the Hamiltonian along with Hamilton's equations to find the equations of motion, using a particle in free space and a harmonic oscillator as examples.
Special Relativity: 4-Momentum, Energy, and 4-Force
Переглядів 1018 місяців тому
In this video I introduce the concepts of 4-momentum and 4-force, the relativistic analogs of momentum and force using f-vectors. I show how conservation of momentum leads to conservation of energy in relativistic systems. The famous E=mc^2 equation is derived and its consequences for chemical and nuclear reactions is discussed.
Special Relativity: Dot Product Invariance
Переглядів 928 місяців тому
In this video I prove that the dot product (also called the scalar product or inner product) of two vectors is invariant relativisticly. In other words, the dot product of two vectors will be the same regardless of what frame the vectors are in.
Special Relativity: The Four-Vector
Переглядів 498 місяців тому
In this video I introduce the four vector, the vector that represents position and time (or space-time) in special relativity. I show a formalism which allows boosts to be thought of as rotations in space-time.
Variable Mass Systems with Lagrangian Mechanics
Переглядів 988 місяців тому
In this video I cover two different techniques for dealing with systems with changing masses using the Lagrangian formalism
A Brief Introduction to Quantum Mechanics
Переглядів 1322 роки тому
In this video, I show you a small sample of the oddities of the quantum world - the world of the very small. The strange phenomena we touch on this video are the quantization of energy, atomic physics, the photoelectric effect, photon momentum, wave-particle duality of matter, the Heisenberg Uncertainty principle, and Quantum Tunneling.
Introduction to Special Relativity
Переглядів 802 роки тому
There are some interesting consequences when things travel with a speed that is close to (or equal to) the speed of light. The study of these consequences are Special Relativity, formulated by Einstein in the early 20th century. In this video I cover some of the basics of special relativity including: time dilation, length contraction, inertial reference frames, Lorentz transformations, energy ...
Optical Resolution and Polararization
Переглядів 222 роки тому
In this video we continue our discussion of wave-like behavior of light. We show how constructive and destructive interference after light passes through an aperture creates a region where two different objects can be distinguished. We state the equation that relates the angular separation distance to the wavelength of light and the diameter of the aperture (Rayleigh Criterion). We then introdu...
Wave Nature of Light
Переглядів 272 роки тому
In this video I discuss the wave nature of light, including a brief discussion about wave-particle duality. I demonstrate how double and single slit experiments exhibit the wave nature of light, and introduce equations detailing the location of the destructive and constructive interference that light will experience when interacting with slits.
Optics: Telescopes
Переглядів 172 роки тому
In this video I show how astronomers use a combination of lenses and mirrors to observe far away objects. We can still use the small lens equations, but the implementation will be slightly different when compared to a microscope. There are also slight modifications that need to be made when dealing with large mirrors, like those found in research grade telescopes.
Introduction to Electro-magnetic Waves
Переглядів 342 роки тому
Introduction to Electro-magnetic Waves
Faraday's Law, Lenz's Law, and Inductance
Переглядів 292 роки тому
Faraday's Law, Lenz's Law, and Inductance
Electric Motors and Electric Generators
Переглядів 202 роки тому
Electric Motors and Electric Generators
Magnetic Fields From Wires (Ampere's Law)
Переглядів 222 роки тому
Magnetic Fields From Wires (Ampere's Law)
Kirchhoff's Laws: Example Problem Solved
Переглядів 422 роки тому
Kirchhoff's Laws: Example Problem Solved
So clutch thanks
The pink derivative terms were not equivalent, which one was correct?
This is fantastic. Thank you.
Thx so much. this is amazingly helpful for me
Can U explain about Null Lagrangians?
Difficult to understand
it was so helpful THANKS
@15:08, what you mean is that it looks like a simple pendulum, not a harmonic oscillator. The solutions to the equation that you wrote down are not sinusoidal functions. The Sin of theta makes this equation highly non linear. Great video nevertheless, keep up the great work!
Thank you sir🥰
Thanks!!
If for every action there is an equal and opposite reaction, shouldn't F12 = -F21?
Yes if thinking about the vectors then there should be a negative in front of one of the forces.
When solving for Vfy at 18:28, I did (-9.8 * 2.02) and got -19.8m/s
Looks like you are correct. I must have entered it into my calculator wrong. If you enter -9.8*sqrt(-40/-9.8) as shown, you do get 19.8 like you said. I will see if I can edit the video.