Question

You hold a ruler that has a charge on its tip 4 cm above a small piece of tissue paper to see if the charge can be picked up. The ruler has -10 HC of charge. The tissue has 3 g of mass. What is the minimum charge required to pick up the tissue paper? με

Answer 1

d = 0.04m Q = -10 mu c m = 0.003kg let the change to q kQq/d^2 = mg 9 times 10^9 times 10 times 10^- 6 times q/(0.04)^2 = 0.003 times 9.8 q = 0.522 times 10^- 9 c q = 0.522 times 10^- 3 n c q = 5.22 times 10^- 4 mu c