After you walk over a carpet on a dry day, your hand comes too close to a metal
ID: 2053158 • Letter: A
Question
After you walk over a carpet on a dry day, your hand comes too close to a metal doorknob and 3.0 mm spark results. Such a spark means that there must have been a potential difference of near to 22 kV between you and the doorknob. Assuming this potential difference, how much charge did you accumulate in walking over the carpet? For this extremely rough calculation, assume that your body can be represented by a uniformly charged conducting sphere 25.0 cm in radius and electrically isolated from its surroundings. Put the answer in the form of "a.bc x 10^(x)" microCoulomb.
Explanation / Answer
V = kq/r = 9*10^9 * Q/.25 = 6000
Q = 1.67 * 10^-7 C