yeah, thanks for Q1.
Why does the polarized material get Q charged on its sides? Doesn't this require that no electric field passes through the polarized material? Usually, the dialectic material isn't able to get polarized enough to completely cancel the electric-field from the capacitor plates, so why should it be different when its height d is shorter than the distance D between the capacitor plates?
edit: it is no longer a problem.
Last edited by Nikitn; February 28, 2013 at 04:57 PM.
A and B can fill a cistern in 4 hours. A and C can fill the same cistern in 5 hours. B can fill twice as fast as C. Find how long C would take to fill the cistern working alone.
Please help. This is supposedly easy but I can't for the life of me figure it out.
Last edited by Jack04; March 13, 2013 at 10:06 AM.
That is a system of equations just itching to made. The resulting matrix and vector looks like this
1 1 0 | 1/4
1 0 1 | 1/5
0 1-2 | 0
Use some internet magic to invert the matrix ...
|-1 2 1|
Multiply by the vector and you get ....
A = 3/20 Cisterns/hr
B = 2/20 Cisterns/hr
C = 1/20 Cisterns/hr
1 Cistern / C = 1/(1/20) = 20 hrs
(**** you Jack, **** you for stealing the Linear Algebra glory that was rightfully mine. One night, I'm gonna come to you, inside of your house, wherever you're sleeping, and I'm going to cut your throat.)
Last edited by Sphere; March 13, 2013 at 10:14 AM.
We have three nodes forming a triangle and place one additional node in the centre. Connect the central node to the other three using three equal inductors and use three equal capacitors to connect the corners to each other.
Does anyone know if this circuit has a special name or how the frequency should be calculated? I got f=1/(2pi*scrt(2CL)) but that seemed far to simple.
Hey, I have another physics question which goes as follows: Decide whether fusion or fission can release energy from the following options:
and some others, but if someone can explain how to figure it out on 1 of the questions I will be able to do the rest myself. How can I know if they(fusion or fission) can release energy from the tasks or not? Cant seem to find anything about it in the book. Can anyone give me the explanation or a hint?
The answers if you are wondering:
c) None of them
If you tried to fuse two iron nuclei (the most common isotope = 30 neutrons) you'd get tellurium except you'd be short on neutrons (stable isotopes of 72 to 74 neutrons). To be stable this new nucleus would need to draw in neutrons
If you split an iron nuclei in half you'd get two Aluminium nuclei (=14 neutrons x 2 = 28) + 2 extra neutrons which would get expelled to make the nuclei stable.
So I would say fission for iron. But I am just a laymen when it comes to nuclear physics.
Finally, a nuclear physics question...
It's a poorly written question to be honest. The important factor is the binding energy per nucleon, as edse already posted. Nuclei generally want to tend to their most stable configuration, which means the state in which their binding energy per nucleon is largest. So in general, fusion is exothermal below iron, whilst fission is exothermal above it.
However. Firstly, one should really specify an isotope. Iron is not actually the element which contains the nucleus with the highest binding energy per nucleon. That claim to fame belongs to nickel (a common misconception). So strictly speaking, one could fuse an isotope of iron with another nucleon to create a more well bound nucleus, which would therefore release energy.
You simply cannot deal with elements when it comes to these things, the isotope is important. For example, 4He is incredibly well bound, whilst 5He isn't.
[Fun fact] In fact, the only reason stellar nucleosynthesis ever makes it past the 4He stage is because of a resonance in 12C (basically 3 4He nuclei) which allows the 4He to fuse. 4He is so well bound that there are no stable mass 8 nuclei, because they all just fission back into 4He nuclei at the first opportunity.[/Fun fact]
Last edited by Jack04; April 04, 2013 at 03:47 PM.
Last edited by Nikitn; April 07, 2013 at 05:06 AM.
Would Matlab be okay?
Does it need to work for any size matrix, or just 3x3?
It is ugly but it works. Just edit the starting matrix
M = [1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16]
D = size(M)
S = D(1,1)
E = S - 1
T = S + E
A = zeros(1,T)
for i = 1:S
for j = 1:i
K = j - 1
row = K + 1
col = i - K
A(1,i) = A(1,i) + M(row,col)
for i = 1:E
for j = 1:i
K = j - 1
row = S - K
col = S - K
B = T+1-i
A(1,B) = A(1,B) + M(row,col)
Last edited by Sphere; April 09, 2013 at 04:37 PM.
A lead weight is disk shaped, and has a hollow center filled with ball bearings. It is dropped down a rod with grooves much like that of a screw. What formulas are relevant to finding the relationship between the force of gravity, the downward velocity of the disk, friction, and the torque (Wrong term?) of the disk?
If it's relevant, I need to find out how to maximize spin and minimize downward velocity.
I need to write a paper about a digital alarm clock display.
It isnt a long paper ,6 pages at max, but truth be told . Though I have a deep interest in exact scineces , I lack any practical knowhow of how stuff works.
ATM for example I am trying to find out how the LED display works with this as serial name : LTC 637C1P
I alrdy found the datasheet here ,but I absolutly have no idea on how to continue on this. It doesnt tell me anything ,except giving me numbers. Could somebody point me to a specific document or book that contains the answer in unridling this?
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