1. ### Classical Textbook for light, heat, waves

There's an undergraduate physics course at my uni that covers these topics and the course description is: Mathematical descriptions for classical physics: oscillations, mechanical waves, electromagnetic waves, physical optics and thermodynamics. Are there any good studying materials/textbooks I...
2. ### I Galilean Invariance and constraints on Forces.

Let's say we have a system of two point particles that can interact with each other by forces that are position and velocity dependent. The forces might or might not be derivable from a generalized potential. Assuming Isotropy of space and homogeneity of space and time, what are the constraints...
3. ### B Conservation of angular momentum in scattering processes

Greetings. So... let us consider a particle moving in the yz plane, coming from the infinite towards a region were a gravitational potential is appreciable. The Lagrangian of the system is \mathcal{L} = \frac{1}{2}\mu (\dot{r}^2+r^2{\dot \phi}^2) + \frac{G\,m\,M}{r} where \mu is the reduced...
4. ### Prove the average external force is Zero

1.Problem statement Prove the average external force of a system of particles N starting from rest and ending at rest is zero. Homework Equations If the system moves periodically prove the av. external force is zero in a period The Attempt at a Solution I dont quite understand what i am asked...
5. ### B Lever, bar, and mechanics why does this happen?

two saipens one known as Alpha who is on the left and the other on right Beta are present, Alpha first presses down on a bar and Beta has to use all of its strength to lift Alpha's hand a distance h a distance, in this scenario the fulcrum is placed close to Beta, now in the next scenario it is...
6. T

### B Why it's easier to push the door from the furthest distance

Why it's easier to push the door from the furthest distance From the pivot point?
7. ### I Solar system simulation errors

Hi, as a side project I am making a solar system simulator in Python, but I am getting extreme inaccuracies. As the image shows - I am comparing the simulation to data obtained from NASA's Horizon. I have written a a basic Verlet integrator in the Python class posten below: import numpy as...
8. ### I Launching a particle at the highest point inside a sphere

If a smooth sphere with radius a is fixed on a plane, and a particle is projected horizontally at the highest point outside/on of the sphere with speed (4ag/5)^0.5, I know that the particle will lose contact with the sphere when it makes an angle of theta with the upward vertical, where theta is...