Abstract
This paper deals with isoperimetric inequalities for polarization, virtual mass and capacity of a body B in R3. The first part of the paper is restricted to certain symmetric regions for which the above mentioned problems may be interpreted as electrostatic problems in R5. This makes it possible to use Brunn-Minkowski type concavity properties for the electrostatic capacity established recently by C. Borell in [3]. In the second part of the paper we construct lower and upper bounds for polarization and virtual mass based on two identities obtained recently in [12] and valid for starshaped regions B