ambiguity in forumlas for average speed & average velocity
I'm going to start with an example: On her way to school, a child discovered that her loonie is missing and there is a hole in her pocket. She turned back and walked 24 m east along the sidewalk. Then,...
View ArticleWhen to objects Attract/Repel(Charges/magnets/electromagnets/etc...)
Hi, In any case where there is a force of attraction/repulsion between two objects, those forces are due to those TWO objects? Two charges/two magnets/two electromagnets When they attract/repel the...
View ArticleDirection of magnetic force
Hello, I know about the right hand rule, but I get confused when velocity and magnetic field are not perpendicular to each other, then how do I determine the direction of the magnetic force? Can I not...
View ArticleAdvantage of using a bigger pulley in belt drive?
Hi : lets examine the following scenario 1. M --------- o where M is a mass, o is a pulley with it's outter radius r attached to a mass by the belt drive -------. frictionless. 2. M ---------O same...
View ArticleDoes entropy drive our conscious experience of time?
From what I can gather, the laws of physics are time sysmmetrical- the exception being the second law of thermodynamics. So could it be that our whole experience of time is driven souly by increasing...
View ArticleDifference between 2-electrode and 3-electrode cell
Hi! I'm currently starting to work with supercapacitors performing cyclic voltammetry of carbon electrodes in 2 and 3 electrodes cell. Since the electrolyte is H2SO4 1M, the scan range is 0.0V to 0.8V....
View ArticleFaraday's law and gauss's law for magnetism apparent contradiction
I was reading here http://www.physicsforums.com/library...tem&itemid=294 gauss law's for magnetism says ∮B⋅dA = 0 but then faraday's law has d/dt ∮B⋅dA in it. Well if its 0 then d/dt of 0 is 0.
View ArticleTwo general questions about wave functions
In my Physics I class, we started learning about wave functions in the form: y(x,t) = sin(kx ± ωt ± ∅) or y(x,t) = cos(kx ± ωt ± ∅) 1) I saw a question where the wave function was structured as: y(x,t)...
View ArticleIs the Earth's Magnetic Field strong and does it fluctuate a lot
I recently learned about Magnetism in my high school Physics class, and it made me think of all the applications there are for it. I was especially interested in magnetic induction. I understand that...
View ArticleVan de Graaff Generator - Shock vs. No Shock?
Hello all, I have a quick, albeit probably ignorant (forgive me) question generated by (bu dum) observations of a van de graaff generator. In particular, two distinct scenarios caused me to question...
View ArticleRelationship between force and Velocity in Magnetic Fields
A negative particle is moving in a uniform magnetic field pointing in the negative k direction. The force on the particle is -i and j. Find the x and y components of velocity. (I left out the numerical...
View ArticleDe-Broglie's explanation on Bohr's Angluar Momentum quantization?
In order to understand about De-Broglie's explanation on Bohr's second postulate,concept of standing waves should be understood. But condition of λ for a given value of length(string) L is given by...
View ArticleIs "E" in Maxwell-Equations really "E"?
Consider a perfectly static and spatially bound magnetic field B ∈ ℝ³ such that B ≠ 0 ; ∂/∂t B = 0 further, a continuous, time-stationary, and spatially bound current j ∈ ℝ³ through that magnetic field...
View ArticlePolarised (polarized) light; EM explanation.
Facets of a rock specimen sparkle brightly In terms of electromagnetism how can I show that a linearly polarised light source can be used to determine that the facets are dielectric rather than...
View ArticleI don't understand Electric Potential in battery
I understand potential as follows: V(r) = Q/(4*pi*e0*r) If current flows from high potential to low potential in a conductor, I am keen to know where is the charge Q located that cause this potential...
View ArticleΔp for total reflection and absorbtion of E&M radiation explanation?
The equation for the change in momentum for total absorption of electromagnetic radiation is ΔU/c and that for total reflection is (2ΔU)/c. How could the momentum of electromagnetic radiation change if...
View ArticleAre these statement true? (Regarding heat flow)?
I'm revising for an exam, and this is what I think I know so far. It will really help if someone can confirm these statements for me. Consider an iron pipe with inner diameter 20mm and outer diameter...
View ArticleDielectric Sphere in Uniform Field
Hi, One of the boundary conditions when solving for the potential outside a dielectric sphere placed within a uniform electric field is [itex]\lim_{r\to 0}\Phi(r,\theta)<\infty[/itex] Can anyone...
View ArticleIf current increases in an coil, what exactly happens?
Hello! I understand that when current is increased throughout a coil, the magnetic field (B) increases it's strength. I try to compare this with a permanent magnet. The magnetic field in a magnet is...
View ArticleIs Maxwell's third law the proof of conservation of energy in E&M?!
Hello! When studying the law I noticed that the change in magnetic field (i.e the magnet's motion) is = to the EMF induced. That proofs to me how the principle of the conservation of energy is applied...
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