Recent content by worldrimroamr

Sorry, I meant to write 1/(sqrt(1 - v^2/c^2)

fatra2 wrote: ------------------------------------ Newton's laws (the three of them) are defined for system of particles in motion, but at very low speed (compared to the speed of light). Therefore, Newton's laws are not wrong, but they are an approximation of the truth, for which the deviation...

The only way I know to deal with the simultaneously rolling and sliding ball down an inclined plane is to use the Lagrangian formulation. It's non-trivial.

Kinetic energy IS conserved in an inelastic collision if you take into account the resulting increase in molecular kinetic energy after the collision and the radiation emitted by the molecules after the collision (aka, heat). The reason the momentum is conserved is that momentum is a vector...

Two comments: 1) "Chaos", or "weak chaos", or "borderline chaos" has nothing whatsoever to do with the Heisenberg uncertainty principle. That is sci-fi, and it's bad physics. 2) The reason we cannot predict the future state of a complex, nonlinear, self-organizing, weakly chaotic system is...

The only meaningful answer above is given by Jeff Reid. What you are doing on a swing is converting gravitational (downward) force to linear (circular) force. When you lean back in the swing, you are transferring part of the downward gravitational force into horizontal motion because of the...

Simple observation: Suppose you hold a beach ball at the bottom of a swimming pool and then release it. It rises to the top of the pool. Have you created potential energy out of nothing? No. First, the gravitational potential gained by the risen ball, mgh, is (disregarding friction, etc.)...

Why is everyone making such a complicate deal out of something that can be expressed so straightforwardly? Gravitational force is exactly proportional to mass. But inertial resistance to motion is also exactly proportional to mass. (That's Einstein's equivalence principle -- the founding...