1. S

    Tension And Definition of elasticity

    The formula of the tension on 2 ropes T giving θ is T=Fg/2*Sin(θ) which means T get closer to infinite when θ is small. But since I can hang on my horizontal bar at home without a problem probably there is no infinite tension on it. I'm guessing there is a fundamental difference between a steel...
  2. A

    Calculating the divergence of electric field using the definition of divergence.

    If I try to calculate the divergence of electric field created by a point charge at the origin then I shall do something like this: \mathbf{E}= \frac{1} {4\pi\epsilon_0} \frac{q}{r^2} \hat r \mathbf{\nabla} \cdot \mathbf{E} = \frac{1}{r^2} ~ \frac{\partial (r^2E_r)}{\partial r} +...
  3. B

    Definition of Gravitational Potential Energy

    Can anyone explain to me the definition of gravitational potential energy? I mean, i understand that it is 'the total work done in bringing a mass from infinity to the point' for any mass at a point, but it just seems too vague. For instance, why is it zero at infinity and negative nearer to the...
  4. L

    What is a good definition of Time?

    Having checked there is not one really good definition of time yet in physics. Not a good definition for time in any dictionary I am aware of either. Here we are using a likely variable for years that we do not have even defined. Toward the end, in the paper I wrote about time and time...
  5. L

    The definition of Luminous

    The emission of light--------so the question still exist how can Maxwell's equations that are derived using Faraday's induction effect that is not luminous (not emitting light) be used to represent the structure of light.
  6. avito009

    New definition of a non inertial frame of reference.

    The present definitions of non inertial frame of reference are vague. Some would define it to mean that a non inertial reference frame is one which does not obey newtons first law. But we can define a non inertial frame of reference in this way. "A non inertial reference frame would be one...
  7. H

    What is the rigorous quantitative definition of the concept of "Energy"?

    First of all I acknowledge you that I posted this Question on many other forums and Q&A Websites. So don't be surprised if you found my question somewhere else. I bet when the experts saw the title, many of them said: "...again another dumb guy seeking answers to useless questions...". But...
  8. P

    Time definition

    Time is defined by the measure of length determined by each humans who make the time together. Each of us has our own theory as time that is done by each feeling(not illusion) for number as question answer. So this question number is all together to make the time theory as the definition of...
  9. M

    Definition of white light according to CIE

    Hi there! I'm doing a project on LED as a light source and one part of the project asks you to define white light according to CIE. (International commission on illumination) I cannot seem to find any really good and precise definition of this. Any help?
  10. J

    Definition of Torque? Do I have the right understanding?

    The textbook defines torques as the measure of the force's effectiveness at making an object accelerate rotationally. Does this mean that a higher torque will get the object to have a higher magnitude in acceleration and a faster time to get the object to reach it's max acceleration...
  11. S

    Definition of a Magnetic Field

    What is the fundamental definition of magnetic (B) field? For example, gravitational field is defined as the gravitational force acting on an arbitrary mass divided by that mass. Electric field is electric force acting on an arbitrary positive charge divided by the charge's magnitude. And both...
  12. P

    Definition of "Energy"

    FYI - We see a lot of people assume that energy can be defined as "The ability do do work." and assume that is a sufficient definition and problem free. But consider momentum. Momentum also has the ability to do work. One can therefore easily mistake the concept of momentum for that of energy if...