Rigid rod moving in potential field
Hi, I'd like to write a program that "simulates" a rigid rod of length L moving in a potential field. The problem is in two dimensions. Friction is assumed to be negligible. The potential field and its...
View ArticleConservation of energy, (lack of) proof
Thermodynamics is clearly based on the assumption that energy is conserved. I ended up discussing this assumption with a fellow student, who states that this assumption can be rigidly justified and...
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Doubling a load.
I came across a diagram of a release mechanism, which shows the operator how to double a release load. I have taking a basic physics course (not advanced) and I can't seem to make any sense of this. I...
View ArticleReason for separate concepts of gravitational vs inertial mass
My mechanics prof today said when setting GMm/r2 = ma, the canceling of the small m is actually a bit nuanced because you have to assume the gravitational mass is equal to the inertial mass (though...
View Articleelectric field between charging capacitor
I am confused about how to find the electric field between a discharging capacitor. For example, let's say I have a fully charged capacitor, such that there is no current flow anywhere. Then there is...
View ArticleThis description of orbits seems wrong to me...
and I would be grateful if those who understand classical mechanics, in particular the physics of orbital motion, could visit this link -- https://earthkam.ucsd.edu/resources/...stays_in_orbit -- and...
View ArticleCan you 'increase pressure' by restricting fluid flow?
I just read this, from a site dedicated to popularizing science: " ...think of air as being like water. If you have a garden hose and put your thumb over the end, the pressure increases and water...
View ArticleRate of flow, or velocity of fluid?
I was looking at a site which described the classic demonstration to illustrate how water pressure increases with depth (shown by punching three holes, one above the other separated by a few...
View ArticleIn acoustics is there something analogous to skin depth in EM?
Hi all The reflection and transmission of a pressure wave at a boundary depends on the relative impedance of the two media. I'm pretty new to acoustics but the textbook I've been looking at doesn't...
View ArticleBatteries in parallel
I want to know how we can find out the net voltage of a circuit where two batteries with different voltages are connected in parallel... Let's consider the problem stated below... If I have a circuit...
View ArticleTrouble understanding derivation of current density..
Current Density = (I/A) I = (Q/t) = (nVq)/t where n is the number of charges, V is the volume, q is the average charge and t is time. nVq/t = n(Ax)q/t = nAvq where v is velocity. Current Density =...
View ArticleDefinition of an Ideal Gas
In another thread, DH and I have been discussing the definition of an ideal gas. DH, who appears to be a physicist, seems to use a definition different from that which we engineers use. I am soliciting...
View ArticleSkipping parts of Landau\Lifshitz Mechanics?
I've recently picked up Machanics by Landau and Lifshitz to brush up on Lagrangian\Hamiltonian mechanics, but this book contains a huge chunk of sections on molecular vibrations\scattering...
View ArticleMoment about an arbitrary axis
Hello, I am having difficulty in understanding how the moment about an arbitrary axis is found as the scalar product of the moment about the origin with the unit vector of the arbitrary axis. Can...
View ArticleAverage Energy and the Equipartition Theorem
The Equipartition Theorem states that each quadratic degree of freedom contributes 1/2 kT of energy. This can be derived for the translational degrees by integrating the average kinetic energy...
View ArticleBanked turns; do we use the x component of normal force or gravity?
I am confused on what the correct way to do this is. In my old physics textbooks, they say that the x component of gravity is responsible for the centripetal force. However, on the internet and for...
View ArticleAre all atoms of a ferro conductor attracted in a magnetic field?
That is what I wondering. When you put a ferromagnetic conductor in a strong magnetic field, the ferro conductor is strongly attracted because of induced strong magnetic dipole moments inside the...
View ArticleForces when lifting a weight and punching
When a person pushes up a weight like in this picture http://www.freefitnessguru.com/Anato...20combined.jpg the weight is exerted on the wrist. So when the weight is stationary, the downwards force...
View ArticlePhysics turns and centripetal force on flat roads
I am confused about this. I learned that the frictional force is pointing towards the center of the circle in circular motion (on a flat road) due to the tires. The thing is, I don't understand what...
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