# Classical Physics

- Principles developed before the rise of relativity and quantum mechanics. Mechanics, Electrodynamics, Thermodynamics, Optics...
 Meta Thread / Thread Starter Last Post Replies Views Views: 644 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Before posting anything, please review the Physics Forums Global Guidelines. Again, for some odd reason, people... Apr22-11 05:26 AM ZapperZ 1 47,691 Hi Folks, Why does a parachutist experience 0g (assuming falling in a vacuum, no drag) when falling towards the... Aug12-14 06:11 AM Lsos 4 267 I'm trying to understand the kinematic equations well enough to explain to someone else, but the analogies I've come... Aug12-14 02:14 AM haruspex 3 169 Hi everyone, A couple of question I was thinking about regarding sound: 1) A sound source is moving at the speed... Aug11-14 07:34 PM billy_joule 6 271 I am not sure if this question even makes any sense, it just popped in my mind while reading a book on special... Aug11-14 02:50 PM Orodruin 37 771 Hi all, I've got a quick clarification question. Generally when the production of electromagnetic waves are... Aug11-14 02:34 PM DaleSpam 2 147 I don't really understand what is the need of giving feedback in the magnetostriction method to produce ultrasonic... Aug11-14 01:27 PM smart_worker 2 249 Hello, in Schwartz's QFT-book it says that: "Classically, a box of size L supports standing electromagnetic waves... Aug11-14 11:10 AM branch 0 173 Before you go through all the trouble of reading all this back story the real information is towards the bottom... Aug11-14 08:35 AM A.T. 17 326 TIR (total internal reflection) is the most common way of producing evanescent wave, e.g. TIR fluorescence microscopy.... Aug11-14 05:34 AM iuvenes 0 207 Just wondering, in order to polarize a light beam with a wire grid you could also get some difraction in despite of... Aug10-14 08:22 PM namati 2 177 I am confused with the wording for a static friction problem; this particular wording also lead me to a conceptual... Aug10-14 09:16 AM KatamariDamacy 13 288 I'd like some help to understand how to calculate "lost work" for irreversible heat transfer across a finite... Aug10-14 02:56 AM PatrickAndrews 12 389 I've been looking into electromagnet design and there is a certain principle/set of equations that are bothering me...... Aug9-14 10:57 PM Simon Bridge 5 309 Folks, I am having difficulty correctly representing a mechanical system within a correct "control volume at an... Aug9-14 03:14 PM bugatti79 7 249 $$\vec{F}=q\vec{v}\times\vec{B}$$ $$\frac{d\vec{F}}{dq}=\vec{v}\times\vec{B}$$ \int\frac{d\vec{F}}{dq} \cdot... Aug9-14 12:20 PM iScience 1 225 Coming from a Chemistry background, we seem to flippantly explain away chemical phenomena using "Coulomb's Law" but... Aug9-14 05:24 AM Delta² 7 283 I managed to confuse myself with a simple thought experiment. I have a space ship that uses mechanical springs... Aug8-14 05:16 AM fulis 2 213 I need to do something for a project. Basically, I need to be able to project a clear image onto a mirror while still... Aug8-14 03:53 AM sophiecentaur 7 242 I am working on making an aluminum truck bed cover for a customer despite my attempts to pass it up, he insists that i... Aug7-14 06:59 PM Metal Man 30 681 What is the minimum speed at which electrons can be emitted? Why is it I never heard of really slow moving electrons,... Aug7-14 04:47 PM Nugatory 27 632 Hi everybody, I encountered this question as an example of what a google applicant is asked: You are shrunk to... Aug7-14 03:06 PM A.T. 8 269 I'm having some difficulty setting up a problem. I'm trying to model the temperature of a thermistor connected to a... Aug7-14 11:09 AM 16universes 32 621 I had an interesting thought regarding the "arrow of time" and, with the hope of getting the opinion of someone... Aug7-14 07:03 AM Philip Wood 8 339 Hi I had a question based on inertia if two balls one heavy and one light are on a bus which is moving with... Aug7-14 06:06 AM sophiecentaur 16 421 Please confirm & answer the following: An atom exposed to an external B-field will experience both a torque on its... Aug6-14 09:45 PM 256bits 1 217 I would like to know if there is any proof as to whether the moment of inertia for two bodies (the masses of each body... Aug6-14 07:12 AM sophiecentaur 6 259 Suppose a point charge is accelerating uniformly. It emits EM radiation. If an observer is co-moving with the point... Aug6-14 03:41 AM vanhees71 5 272 Can a magnetization density that is compactly supported be the gradient of a scalar field? This question relates to... Aug6-14 03:35 AM vanhees71 4 218 I am trying to calculate heat transfer from an inclined flat plate under free convection conditions. I am referring to... Aug5-14 02:08 PM jlefevre76 6 220 What does p = mv really mean? For example, why is there a physical law based upon the product of mass and velocity?... Aug5-14 01:43 PM olivermsun 57 1,769 Hello Forum, The 1D harmonic oscillator is an important model of a system that oscillates periodically and... Aug4-14 09:59 PM Simon Bridge 13 357 Hello, I'm building a model train control system, and would like to use real world values and physics to control the... Aug4-14 06:37 PM KaiGrid 6 219 Two questions: 1.) Consider a hollow conductive sphere that's initially charged. These charges will distribute... Aug4-14 02:57 PM iScience 2 379 See, we know that different electrical appliances in our house require different amount current to work .now first if... Aug4-14 02:41 PM CWatters 9 301 Question about moments and torques. I understand that torque is defined as τ=Fs and understand where this comes... Aug4-14 02:17 PM CWatters 2 214 If I have ice, water and vapour at the triple point and they are in equilibrium at a temperature of 273.16. Does this... Aug4-14 09:42 AM vjacheslav 3 213 I have read that electric field inside a cavity of irregular conducting surface having any charge is zero.how is this... Aug4-14 09:07 AM Nugatory 3 193 What is the potential of Earth with respect to (wrt) infinity (C=710uF)? I am assuming that infinity is the correct... Aug3-14 06:21 PM DaleSpam 1 193 Whay is it that when we release air from our mouth when it is little open then the cold air is released but when we... Aug2-14 06:58 PM A.T. 7 305 I have some questions about electrons flow. 1)Lets say we have a simple circuit with a metal wire and a battery... Aug2-14 11:10 AM voko 7 348