Falling bodies and terminal velocity
Is it correct to assume that two objects, with different masses, dropped from the same height at the same time will fall at the same rate until one of the objects reaches its terminal velocity? What...
View ArticleDouble slit experiment doesn't work
I took a piece of carton and cut out to strands in it. When I shine the line through it, it only projects the two strands on the other side. I tried it with every light in my house but it still didn't...
View ArticleHow to calculate pad deformation
Could someone please show me how to calculate the deformation of a pad (ideal material with the same elasticity at all directions) under a cylinder ? Thank you very much.
View ArticleRolling without slipping: Why point of contact has zero velocity
In rolling without slipping, why does the point of contact have zero velocity relative to the ground? If so, how can the point of contact move relatively to the ground? (It has to move relative to the...
View ArticleDifference betweem conduction and diffusion?
On an undergrad engineering level of talk, is there any difference between conduction and diffusion ways of heat transfer? Conduction occurs because of the vibrational freedom of atoms. And diffusion...
View ArticleWhy is convection heat transfer rate independent of relative velocity?
Convection heat transfer rate decided by Newton's cooling law doesn't have a relative velocity between the fluid and the solid surface term. But intuitively doesn't blowing faster on a hot surface make...
View ArticleDetermine the polarity of the reflected EM wave.
Attached are the drawings. Does the polarity Eof depend on [itex] \Gamma =\frac {\eta_2-\eta_1}{\eta_2+\eta_1}[/itex] So if [itex]\eta_2<\eta_1[/itex], the Γ is negative and the polarity of the...
View ArticleApplication of entropy , Gibbs and Helmholtz
to see anything will occur spontaneously or not. A system is isolated, we will look at the entropy. A system at constant temperature and volume, we will look at Helmholtz A system at constant...
View ArticleThought experiment
My brother and I were discussing fuel consumption which lead to this thought experiment. Let's say you have two identically shaped spaceships of different masses traveling in outer space where they are...
View ArticleHow can I negatively charge a piece of lead? (A Skeptic's question)
Hi everyone, I don't mean to offend anyone (actually I'm looking for help), it's just that I am having a hard time believing the superposition principle and below is the reason why I cannot believe it...
View ArticleEquivalence principle implies uniformly accelerated charge doesn't radiate?
Does a uniformly accelerated charged particle radiate em waves? The equivalence principle says that a particle in uniform acceleration is equivalent to a particle at rest in a gravitational field. A...
View ArticleHeavier mass of gas
Ok, so the other day I was chatting with a friend of mine, and this doubt came up... It is my understanding that hot air rises over cold air in the atmosphere because, being hotter, it is less dense...
View Articlemotion detector for iPad
I'll be teaching an AP Physics class in a few weeks. Usually labs are equiped with lots of desktop computers, to which I can add stuff like motion detectors: devices that can input velocities into the...
View ArticleEnergy Stored in a spring
Why is the energy stored in a spring 1/2 * distance * force? Isn't work just force * distance?
View Articleeyepiece -- Huygens versus Ramsden
Hi,can someone explain me this picture? : http://www.accessscience.com/search.aspx?rootID=792797 I dont understand,what it means,Im reading the description,but it doesn t help me.It looks,like if I use...
View Articlecalculate the change of volume from volume expansion coefficient
β= (1/v)(∂v/∂T)constant pressure. What is the v represent? molar volume? If I am given the β and the change of temperature, how to calculate the change of volume? or it is not enough information to...
View ArticleWhy does a charged capacitor provide current to a circuit?
I have a conceptual doubt concerning capacitors. Suppose that I connect the terminals of a resistor to a charged capacitor, so that current will flow through the resistor. Usually, in calculations...
View ArticleMotion of a charged particle
hi PF, i got a question in my mind while studying electrostatics that Will a charged particle loose its charge if it travels with a speed a) Less than speed of light? b) Close to speed of light?
View Articlecalculating the force of applied by a vise jaw
Its been many years since i studied mechanics at school and I need to know how to calculate the force applied to a vice jaw by turning the vice handle .i am guessing that it could be worked out by...
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