Physics question on Coulomb

Question

Hi, I need help with the following : 

 

If you are wearing rubber sole shoes and a cat rubs himself on you, who would exchange a charge? Which of you is positivly charged and which of you is negatively charged? Assuming you two exchanged 3x10^9 electrons, what is the charge on you in coulombs and what is the charge on the cat in coulombs?

 

 

I know that the cat would be negatively charged because fur has a greater attraction for electrons but I don't know how to do the last two questions. 

Answer 1

If you are wearing nylon or wool, then the cat becomes negatively charged since the those materials give up electrons more easily than the cat's fur. But if you are wearing silk then the cat gives up the electrons to the silk, and the silk becomes negatively charged.

The object that gains electrons becomes negatively charged and the object that loses the electrons is positively charged.

One electron has a charge of - 1.6 x 10^-19 coulombs. That should help you to figure out the charge on a whole bunch of electrons.