« first day (2742 days earlier)      last day (22 days later) » 

HNQ
3:26 AM
1
Q: Where does the energy stored in inductor go on opening the switch?

nimit jainSuppose we have a simple RL circuit. At $t=0$, I close the switch so that current starts flowing in the circuit. When the steady state is achieved, current $i=\frac{\epsilon}{R}$ would be flowing in the circuit due to which an energy $\frac{Li^2}{2}$ will be stored in the magnetic field lines on ...

 
 
3 hours later…
HNQ
6:19 AM
1
Q: Do electromagnetic waves contain electrons?

Richard WestmorelandI understand that EM waves are oscillating electric and magnetic fields. But doesn't this mean that the wave itself contains charged particles that generate the fields?

 
 
7 hours later…
HNQ
12:53 PM
2
Q: Why can the surface temperature of a star be calculated using the Stefan-Boltzmann Law

Will RosenbergI calculated the surface temperature of the sun using the energy flux of the sun and the Stefan-Boltzmann equation, as is seen in the beginning of this post, but I am confused on how this gives the surface temperature of the sun. Is the T we calculated not the average temperature of the star, sin...

 
 
6 hours later…
HNQ
6:37 PM
1
Q: Why does something round roll down faster than something square?

Sextus Empiricus Why does something round roll down faster than something square? That's a question given to me by my five year old son. So let's not get into detailed discussion about what is 'square' and what is 'round' or what is 'rolling down'. I thought that this might be interesting enough to ask here. Th...

 
 
5 hours later…
HNQ
11:57 PM
1
Q: If motion relative to a frame of reference is purely relative, how do we account for the work done to move relative to the frame of reference?

Justin PalmerI get the idea that everything is in motion, and there's no absolute reference frame for everything. But when we consider local events, like a train passing through a town, I have trouble accepting the notion that we have no principled way of asserting the perspective that the train is moving rel...

 

« first day (2742 days earlier)      last day (22 days later) »