Recent content by Manolisjam

so i Keep the vollume inside the integral!

##E4πr^2=\frac{q+ \int ρVdr}{ε_0} ## is the right one?

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I have a non conducting sphere with a charge ρ=A/r per uni vollume A is constant. suppose there is a cavity in the centre and within a particle of charge q. i want to find the E inside the sphere in respect with r. Homework EquationsThe Attempt at a Solution for radius equal of the cavity i get...

Its zero the rest of the math is ok? SO the double sum is zero.

1.Problem statement Prove the average external force of a system of particles N starting from rest and ending at rest is zero.Homework Equations If the system moves periodically prove the av. external force is zero in a period The Attempt at a Solution I don't quite understand what i am asked...

if you can show me another way for the time. i still haven't understant what you are trying to help me do.

At the 0 point using conservation energy i get something like u_a^2+u_g^2=2gsinθl now i know dx/dt=u_a=lsinθdθ/dt . find same way u_G now squaring those. andi plugging them in conservation i get Ldθ/dt=sqrt(2sinθ) this is a differential eq separable. find θ(t) and solve for θ=π/2 but i can't...

Solved it!

Laso could you classify the diffculty of the problem 1-10. for a math undergrad .

Ok I am trying to do what you said i get the same with i did already .what is different? MY potential energy was zero when G was at L distance so if its zero at the same height i sa the final potential energy is the initial i found.

some1 else told me to llok at the relaton between the accaleration o A in x axes withs its component to the direction AG and then the relation between Gs accelaration and that component

are you sure conservation will lead me to finding the time of impact?

sorry for being rude I am just frustrated.. really appreciate you wasting your time with me.

ive been trying 2 days now straght . all . I've asked other people no1 will give me a full answer so i can study it and understant it. because that the policy .. i give up nvm i give up.. its 3 day straight I am just doing this thing... and no1 can give me a full answer since i can't derive it..gn