wrobel's latest activity

I mean that one should first study kinematics and after that dynamics. Any motion is defined with respect to some frame only. So what?

It is a very bad idea to throw kinematics and dynamics in the same heap

I am afraid this notion is not completely formalized. Say a lab frame is an inertial frame you are sitting in and with respect to which...

It is a covector in the Lagrangian formalism but not in this context. Yes ##\frac{\partial L}{\partial \dot x}## is a covector on the...

That's wrong. Angular momentum is a vector. It is a pseudovector to be precise. Just by definition: ##\sum_k m_k\boldsymbol...

I can just explain what one actually should understand regarding this stuff. Assume we have a system of particles ##A_1,\ldots, A_N##...

So it's basically the "extra" velocity something like a car's wing mirror has if you subtract the car's COM's velocity? I don't know any...

In face-to-face communication I would first ask to write down the formula of kinetic energy of a rigid body and then to provide...

There is a nice theorem. Let ##f,f_1,\ldots, f_n:X\to\mathbb{R}## be linear functionals defined on a vector space ##X##. Theorem. Assume...

Gyroscopic forces do not do work. Just by definition because the gyroscopic forces are ##Q_j=\omega_{ij}(t,x)\dot x^i,## where...

I do not understand what this means. By definition a vector field on a manifold ##M## is a function ##v:M\to TM## such that ##v(x)\in T_xM##

The set ##B\times \{v_p\,|\,p\in B\}## contains an element ##(p',v_p)## with ##p'\in B,\quad p'\ne p##. Such a definition of a vector...

It depends on definitions. You can take this formula as a definition. On the other hand we can start with an ordinary differential...

You can define a vector field as follows. Assume that in any coordinates ##x=(x^1,\ldots,x^m)## in a domain ##D\subset\mathbb{R}^m##...

I do not know if this construction is contained in textbooks but it is surely contained in the collective unconscious :) Let...