Recent content by Hamal_Arietis

  1. Hamal_Arietis

    Does a Voltmeter's needle jump?

    Thank you, I did not concern about the wires.
  2. Hamal_Arietis

    Does a Voltmeter's needle jump?

    a) the magnetic field does not change if the magnet rotates, but the conductor rotate so EMF is induced and I found the answer for a) situation In b) situation, I think it is so strange because there are no relative movement between conductor and magnetic field. And if you ask me what part of...
  3. Hamal_Arietis

    Does a Voltmeter's needle jump?

    one connect to the axle and the other end to a sliding contact, you can see in the image.
  4. Hamal_Arietis

    Does a Voltmeter's needle jump?

    I think Voltmeter's needle will not jump in both situations. But the answer is yes. I am going to use this to explain why. The reasons to create the voltage are by - The changing by time of Magnetic field - The move of the object in magnetic field In both situations, they are not occur so I...
  5. Hamal_Arietis

    How Do You Calculate the Electric Potential of a Square Plate?

    I tried it. And I found the answer. by considering ##d=d_0## as the potential origin. The potential is $$V=\frac{\sigma}{\pi\epsilon_0}(a\log{(\frac{d_0^2+a^2}{d^2+a^2}})^\frac{1}{2}+d_0\tan^{-1}(\frac{a}{d_0})-d\tan^{-1}(\frac{a}{d}))$$ It seems correct because when I calculate the limit of V...
  6. Hamal_Arietis

    How Do You Calculate the Electric Potential of a Square Plate?

    $$\int\frac{dx}{\sqrt{x^2+d^2}}=log |x+\sqrt{x^2+d^2}|+C$$ but my fomular is $$ \int\frac{rdr}{\sqrt{r^2+d^2}}=\sqrt{r^2+d^2} +C$$ the problem is when I replace ##r=\frac{a}{cos\theta}##, the integral became more complicated. the double integral became $$\int_0^{\frac{\pi}4}...
  7. Hamal_Arietis

    How Do You Calculate the Electric Potential of a Square Plate?

    I found out the equation of electric potential, that is V=\int_{-a}^a \int_{-a}^{a} \frac{σdxdy}{4 \pi \epsilon_0\sqrt{x^2+y^2+d^2}}=\int_{0}^a \int_{0}^{a} \frac{σdxdy}{\pi \epsilon_0\sqrt{x^2+y^2+d^2}} but I couldn't calculate the integral. It seems convenient if we use the polar coordinate...
  8. Hamal_Arietis

    Integral of f(x): Get Answer Here

    $$A=\int_0^{\frac{\pi}{a}}f(t)\cos at\,dt$$ $$A=\int_0^{\frac{\pi}{a}}( 1 + A \cos 2at + B \sin 2at)cos(at)dt$$ $$A=\frac{4B}{3a}$$ And $$B=\int_0^{\frac{\pi}{a}}( 1 + A \cos 2at + B \sin 2at)sin(at)dt$$ $$B=\frac{2}{a}+\frac{2A}{3a}=\frac{6+2A}{3a}$$ Then solve both equation...
  9. Hamal_Arietis

    Integral of f(x): Get Answer Here

    Sorry, I don't understand your idea. Can you give me some document about it?. This problem is an examination for high school students to entrance university. I have learned that: If ##F(x)=\int_a^xf(t)dt## then: $$\frac{d}{dx}F(x)=\frac{d}{dx}\int_a^xf(t)dt=f(x)$$
  10. Hamal_Arietis

    Integral of f(x): Get Answer Here

    I try to find f'(x) by the fundamental of calculus before but it don't have answer
  11. Hamal_Arietis

    Integral of f(x): Get Answer Here

    Both equations are: $$f(t)=A+1$$ $$f(t)=1+Acos(2at)+Bsin(2at)$$ So ##A=Acos(2at)+Bsin(2at)## and I transfer it into: $$\int_0^{\frac{\pi}{a}}f(t)cos^2(at)dt=\int_0^{\frac{\pi}{a}}f(t)sin^2(at)dt$$
  12. Hamal_Arietis

    Integral of f(x): Get Answer Here

    Oh, I see: $$A=Acos(2at)+Bsin(2at)$$ $$A(1-cos(2at))=Bsin(2at)$$ $$2Acos^2(at)=2Bsin(at)cos(at)$$ $$cos(at)(Acos(at)-Bsin(at))=0$$ So we have: $$\int_0^{\frac{\pi}{a}}f(t)cos^2(at)dt=\int_0^{\frac{\pi}{a}}f(t)sin^2(at)dt \Rightarrow f(t)cos^2(at)=f(t)sin^2(at)\Leftrightarrow f(t)=0 ∨...
  13. Hamal_Arietis

    Integral of f(x): Get Answer Here

    Thanks, I understood. Another equation is: $$f(t)=\int_0^{\frac{\pi}{a}}f(t)cos(at)dt+1=A+1$$ But we must find f(t), A, B while we have 2 equations?
  14. Hamal_Arietis

    Integral of f(x): Get Answer Here

    Homework Statement Find f(x) if:(a∈R) $$f(x)=\int_0^{\frac{\pi}{a}}f(t)cos(at-2ax)dt+1$$ Homework Equations $$f(x)=\int_{a}^{b}f(t)dt=F(a)-F(b)$$ $$\int{udv}=uv-\int{vdu}$$ The Attempt at a Solution I tried to use the fundamental of calculus and integration by parts but they don't have answer...
Back
Top