I thought I would add to this thread instead of making another one.
My question is this: why do we calculate power spectrums at all?
This makes sense in the context of voltage (power = V2/R), but I've seen this used in numerous other contexts with other units for the signal.
For...
Thank you for your answers (I did construct the circuit physically, and measured an alternating voltage with an oscilloscope).
It seems that I have placed too much faith in circuit theory. It was good to confirm my suspicions.
My follow-up question then would be (and I don't even have an...
I felt that the schematic looked awkward, but decided not to do anything about it :smile: Sounds like adding the extra piece would have fixed it.
That is what I thought as well.
But, what about this: the AC source is creating a constantly changing voltage.
Consider the rising part of...
Please see the attached illustration.
This is clearly an open circuit.
The voltage source is producing a voltage at some amplitude and frequency.
If one were to measure with an oscilloscope the potential difference at the point where the mouse pointer is with respect to the ground, what would...
There we go! Now it makes a lot more sense.
I was under the impression that it was a circle of radius (ec) because of the way in which the arc is drawn.
If you look at the illustration, the arc is clearly too large to belong to a circle of zero radius.
I guess the illustrator...
Hey,
I think I understand Huygens' principle :smile:
Let's consider the wavefront (eh), and call the time when the wave passes through this front t1.
Then, let's consider the time interval that is equal to \frac{\lambda_{1}}{\nu_{1}}.
This is equal to the period (T).
Let us then...
Hey,
Most of what you are saying makes sense to me.
However, the quoted part is still unclear.
Huygens' principle states that:
Every point on a wave-front may be considered a source of secondary spherical wavelets which spread out in the forward direction at the speed of light. The new...
I've figured out why I was wrong (by looking in a textbook).
What was wrong was that for the second case, the induced charge needed to be taken into account.
So, the charge enclosed by the volume was no longer q, but was q-q', where q' is the induced charge of the opposite sign.
Once that's...
I am having difficulty accepting an illustration from a physics textbook. The illustration is attached.
For part (b), the authors state that hec is a right triangle.
Also, the wavefront (cg) is clearly not parallel to the wavefront (he).
However, isn't this impossible?
If point (c) on the...
A derivation of the capacitance for a parallel plate capacitor is as follows:
[ assume uniform field, plate area is infinite in relation to the separation, the conductors are perfect conductors ]
So, V=Ed
where
V=voltage difference between plates
E= electric field (uniform)...
This page contains one derivation for the potential energy:
http://www.shef.ac.uk/physics/teaching/phy205/lecture_4.htm"
Result: U=-pEcos\theta
where
E = magnetic field's magnitude
P = dipole moment = d*Q
d= distance between + and - charge
Q= charges' magnitude
\theta = angle between the...
You are right - thanks for catching that (I did have the wrong height). :biggrin:
I also agree that an external force does not come from the system.
But, I don't think that mechanical energy is conserved, because the energy required for throwing the block comes from chemical energy (the food...
I think that I know why the equations don't have non-complex solutions.
The conservation of mechanical energy can't be applied, because the force created by the human is, in fact, an external force, even though it is coming from within the system.
This force is a result of chemical changes of...