Find the electric field at the top point of a right circular solid cone of charge Q, uniform density. The cone has a radius a and a height h.

Find the electric field vector anywhere in the plane of a dipole. Let the charge value on one charge be q. Let them be separated by d. Let the origin be in between them. And say they are each on the y axis.

suppose I have a square of charge with a uniform charge density lying in the x-y plane with one corner at the origin and the other corner at (L,L,0). The total charge is Q. Determine the electric field at (0,0,Z).

A ring (mass 4 M, radius 1 R) rotates in a CCW direction with an initial angular speed 2 ω. A disk (mass 2 M, radius 2 R) rotates in a CW direction with initial angular speed 4 ω. The ring and disk "collide" and eventually rotate together. Assume that positive angular momentum and angular velocity values correspond to rotation in the CCW direction.What is the initial angular momentum Li of the ring+disk system? Write answer in terms of MR2ω.   What is the final angular velocity ωf of the ring+disk system? Write your answer in terms of ω.

In the figure a smallI, nonconducting ball of mass m = 0.92 mg and charge q = 2.0 x 108 C (distributed uniformly through its volume) hangs from an insulating thread that makes an angle 0 = 39° with a vertical, uniformly charged nonconducting sheet (shown in cross section). Considering the gravitational force on the ball and assuming the sheet extends far vertically and into and out of the page, calculate the surface charge density o of the sheet. n, 4 ++++ + + tE + +