1. ### Studying Is learning derivations of formulae always very important?

I understand that it is useful to learn and remember the derivations of formulae in most cases. However, I tend to forget the derivations of several formulae, especially those in optics and dynamics. For a moment, let's forget the examinations. I wish to pursue higher studies in applied...
2. ### Which path has the shortest time?

Guys I have the following homework problem to solve: There are 2 given points in a plane. If we take a point-like object with mass m and take it to the "higher" point what path should it go on to reach the other point in the shortest possible time. Only gravitational force affects our point-like...
3. ### Can someone explain this derivation?

Homework Statement I've been looking at examples of motion derivations for my class, and it's honestly just very confusing. I heard Dynamics should prep you for this but I must have had a very poor course because we never had to understand geometry and physics to this degree... Homework...
4. ### Deriving Electric Field Inside Plastic Rod Using Gauss's Law

Homework Statement A straight circular plastic cylinder of length L and radius R (where R ≪ L) is irradiated with a beam of protons so that there is a total excess charge Q distributed uniformly throughout the cylinder. Find the electric field inside the cylinder, a distance r from the center...
5. ### I Proof derivative of a vector following precession motion

I do not get some points of this proof about the time derivative of a unit vector $\hat{u}$ (costant magnitude) which is following a precession motion. The picture is the following. I want to prove that $$\frac{d\hat{u}}{dt}=\vec{\Omega}\wedge \hat{u}.$$ I'm ok with almost all the proof...
6. ### Derivation of Cholesky Decomposition

Homework Statement Derive Cholesky Decomposition for a 3x3 matrix Homework Equations IN: S is Real matrix with dimensions 3x3 and is Symmetric and semi-definite Out: L is a Real matrix with dimensions 3x3 such that S=L*L^t L is lower-triangular The Attempt at a Solution We learned this in...
7. ### Lorentz Transformations with Special Relativity Derivation

Any advice on my derivation layout?
8. ### Uniform Circular Motion Background theory?

Hi Guys, new poster here. I am currently doing a practical report on Uniform Circular Motion, where we had to swing a rubber stopper around attached to a length of string and mass. I have to do a write up, including the background theory. I have searched everywhere but I have found no clear...