If you lay one tape (A) sticky side up on a table (without discharging it) and bring the other (B) close above it you should be able to determine the distance at which the repulsive Coulomb force is equal to the force of gravity on tape B. Assume that the charges are equal on the two tapes (they were prepared the same way!), and the mass of scotch tape is roughly 1 gram/meter (it is pretty accurate, I just measured a roll of 30 m, and got 32 g, including the plastic in the middle).
a) Using Coulomb’s Law, calculate how much charge is on a 2 cm long piece of tape. As a guide I find that the top tape floats above the bottom tape when they are about 1 cm apart (try it!).
b) How many extra electrons are on each piece of tape?
c) What main assumption you make in solving this problem using Coulomb’s Law? Explain why you made this approximation? Is it a good assumption?
If you lay one tape (A) sticky side up on a table (without discharging it) and bring the other (B...