An arrangement of positive charge forms a semicircular structure with radius R, depicted in the illustration. The linear charge density along the semicircle is given by the equation A Xocose. The aggregate charge on the semicircle is Q. Determine the complete force exerted on a charge of q situated at the central point P.

The figure below shows a small, charged bead, with a charge of q = +41.0 nC, that moves a distance of d = 0.174 m from point A to point B in the presence of a uniform electric field  E  of magnitude 255 N/C, pointing right. A positive point charge q is initially at point A, then moves a distance d to the right to point B. Electric field vector E points to the right. (a) What is the magnitude (in N) and direction of the electric force on the bead? magnitude Ndirection     (b) What is the work (in J) done on the bead by the electric force as it moves from A to B?  J (c) What is the change of the electric potential energy (in J) as the bead moves from A to B? (The system consists of the bead and all its surroundings.) PEB − PEA =  J (d) What is the potential difference (in V) between A and B? VB − VA =  V

A total amount of positive charge Q is spread onto a thin non-conducting circular annulus of inner radius a and outer radius b. The charge is distributed in a way so that the charge density per unit area is given by ? =??3, where r is the distance from the center of the annulus to any point on it and k is a constant.(a) Find an expression for the total charge Q on the annulus. (b) Find an expression for the potential V at the center of the annulus in term of Q, a and b

A negative point charge Q1, is located at the origin. A rod of length L is located along the x axis with the near side a distance d from the origin. A positive charge Q2, is uniformly spread over the length of the rod.  After integrating the force from each slice over the length of the rod, the magnitude of the electric force on the charge at the origin can be represented as the following: F = (k |Q1| |Q2|) / (d (d + L)) Let L = 2.22m, d = 0.42m, Q1 = -6.29µC, and |Q2| = 11.1µC. Calculate the magnitude if the force in newtons that the rod exerts on the point charge at the origin.