1. The problem statement, all variables and given/known data 1. Given a coloidal polystyrene particle with a diameter of 350 nm and a surface charge of 7.73. µC cm-2 evaluate: a) the electrostatic energy under and applied voltage of 100 mV 2. Relevant equations particle charge density: ρ = (3Q)/(4πR^3) U0 =∫V (r)dq 3. The attempt at a solution V(r)=q(r)/4πε0r U0 =∫V (r)dq=(4π(ρ^2)R^5)/15ε0 BUT I DO NOT UNDERSTAND APPLIED VOLTAGE WHAT IT MEANS?