1. The problem statement, all variables and given/known data A person scuffing her feet on a wool rug on a dry day accumulates a net charge of -73 µC. How many excess electrons does this person get? 2. Relevant equations so i did 73x10^-6 / 1.602x10^19 and i got 4.5x10^14 but one of the questions is By how much does her mass increase? 3. The attempt at a solution I have no idea how i would go about and in finding this.