Recent content by paulfr

The magnetic flux lines using the Right Hand Fist/Grip/Screw Rule ... circle around the wire perpendicular to the direction of the current. Since Flux is B dot A = B A cos theta, since theta is 90 degrees, the flux thru the cylinder is zero, 0. ...Theta is the angle between the normal to the...

In teaching HS Physics part of which is Electric Circuits, I have discovered a rule / technique for parallel resistors that I never encountered in all my 30+ years in electronics engineering, nor in any textbook on Circuits. It is what I call " The N + 1 Rule " We all know the Reciprocal...

Thanks Mark44 Yes if the integral is finite, the series is convergent. I did the integral again and got 0.549 as a lower bound Adding in f(N) = f(2) = 1/3, the upper bound is 0.882 and 3/4 fall between these bounds. This lower/upper bound information is from Wiki ; Integral Series Test. Thanks...

Sammy S Thank you. I can see the 3/4 when I find the 8 terms for n= 2,3,4,5. It telescopes after 2 iterations of n. And if the second term of the solution in the OP were not - 1/2n but was + 1/ 2(n+1) I would have it understood completely. [Maybe the teacher made an error ?] I did the Integral...

No I can not. But a p-series is rather basic so if I knew how to do this one I will likely induce how to do others. First problem is the hardest one. I know I need to work an improper integral, but can not get to π2 / 6

OK how about an easier question. Why is limit n=> inf ∑ 1 / n2 = π2 / 6 ?? When I find the Antiderivative I get - 1/x Where does the π come from ??

I did and got A = - 1/2 and B = 1/2 ==> [ - (1/2) / ( i + 1 ) ] + [ (1/2) / ( i - 1 ) ] which does not seem to help. Where is that 3/4 coming from ? I do not understand what vela is trying to tell me. I know I am way off base here.

Yes, the stated problem says to find the limit for sn. Can you give me a clue what to do to get on track here ?

Infinite Series convergence and divergence. PFD will give A / i +1 + B / i - 1 and that does not look in any way like the given solution.

Homework Statement and in this case we have, [PLAIN]http://tutorial.math.lamar.edu/Classes/CalcII/ConvergenceOfSeries_files/eq0016MP.gif[PLAIN]http://tutorial.math.lamar.edu/Classes/CalcII/ConvergenceOfSeries_files/empty.gif Homework Equations I can not see how they get either of...

There is no acceleration in the x direction. So sx(t) = s0x + v0x t 40 = 0 + 90 cos [theta] (0.75) cos [theta] = 0.593 theta = ArcCos 0.593 = 53.7 deg is correct You would need the y direction information ONLY if you were not given the time of travel. But it was given so you are...

Homework Statement A 300 eV electron is aimed midway between two parallel metal plates with a potential difference of 400 V. The electron is deflected upwards and strikes the upper plate as shown. What would be the kinetic energy of the electron just before striking the metal plate? Homework...

The bowling ball feels a greater Force from the Gravitational Mass of the Earth than the marble as calculated with Newton's Universal Law of Gravitation. But it also has more Inertial Mass, the tendency to resist a change in motion. The two effects balance so that the bowling ball accelerates...

Can anyone explain this ? A plane is flying overhead and casting a shadow on the court. How can this shadow move backwards given we know the plane is not flying backwards ?? http://tinyurl.com/planeflyingckwards

I believe you need to divide by 2 factorial, NOT 2. Yes it is the same in this problem But not if 3 or more are the same.