A disk of radius R has positive charge uniformly distributed over an inner circular region of radius a and negative charge uniformly distributed over the outer annular (ring-shaped) region . The surface charge density on the inner region is +σ, and that on the annular region is −σ. The electrostatic potential at P, located on the central perpendicular axis a distance z=R from the disk center, is zero.

What is a?

Express your answer in terms of R. Express the coefficients using three significant digits.

i think the answer is a, hope this is right, that would be my best guess.

the following is queen elizabeth’s purposes:

- to encourage the parliament that the technique of picking successors to the seat based merely on birthright needs to be reviewed.

- (not) to convince the parliament that her kid should not be measured as a likely choice for heir to the english power.

- to persuade the parliament that merely since she has a child does not assure that the kid will be a capable leader.

- to sway the parliament how shattering it could be if they proceeded discourteously concerning her or her child.