Physics

Problem

Two identical point charges

+1\,\mu\text{C}

each are placed

30\,\text{cm}

apart in air. Calculate the work that must be done to increase their separation to

90\,\text{cm}

, assuming the process is carried out slowly so that kinetic energy changes are negligible. a)

+2.0\times10^{-2}\,\text{J}

-4.0\times10^{-2}\,\text{J}

-2.0\times10^{-2}\,\text{J}

-1.0\times10^{-2}\,\text{J}