12:13 AM
5

How can I interpret the normal modes of this mechanical system? The equations of motion for the system are as follows: $$\left[\begin{array}{ccc} m_{1}\\ & m_{2}\\ & & 0 \end{array}\right]\left\{ \begin{array}{c} \ddot{u}_{1}\\ \ddot{u}_{2}\\ \ddot{\alpha} \end{array}\right\} +\left[\begin{ar... 4 I am an electrical engineering by trade, working on the analogue part (Transmitter & Receiver) of a quantum optical communication channel. By this, I mean I have not much experience on things quantum. There are, however, some notions or concepts that I would like to understand, but no matter how ... 5 To see where QCD starts to differ from the behavior of EM fields, we might begin by looking at the classical field. A search brings up [question 339978] and [question 360061] but no answer is found there. With the usual [QCD Lagrangian] definition:$$\begin{align} \mathcal L_{\text{QCD}} &= \bar\...

1 hour later…
1:16 AM
7

An even number of books (say four) are held in the manner shown in the figure. It is obvious that if we apply a large force inwards, we can increase the normal force, and hence the friction which keeps the books in equilibrium. Assume all the books are identical. On considering the equilibrium o...

2 hours later…
3:29 AM
2

I have a physics problem in my book, where a spring is compressed and a ball is laying in the end of the spring. When the spring is released the ball will reach a certain speed. In the solution it says that all the spring potential energy will be converted into the kinetic energy of the ball. Wha...

14 hours later…
5:14 PM
6

I would like help in understanding something that has been causing me a lot of trouble recently. Why is energy always related to time in physics. Whether it is in the 4-momentum, the energy-time uncertainty principle, hamiltonian mechanics. And especially how is the hamiltonian the generator of t...