The current is defined as the ratio between the charge Q flowing through a certain point of a wire and the time interval,

:

First we need to find the net charge flowing at a certain point of the wire in one second,

. Using I=0.92 A and re-arranging the previous equation, we find

Now we know that each electron carries a charge of

, so if we divide the charge Q flowing in the wire by the charge of one electron, we find the number of electron flowing in one second:
Answer:
5.714 hours / day
Explanation:
<u>Calculate the hours used in that week </u>
120000 / 3000 = 120 / 3 = 40 hours a week
<u>Calculate the amount it is used in one day</u>
40 / 7 = 5.71428571 hours or 5.714 hours/day
The equation Q=CV (Charge = product of Capacitance and potential difference) tells us that the maximum charge that can be stored on a capacitor is equal to the product of it's capacitance and the potential difference across it. In this case the potential difference across the capacitor will be 12.0V (assuming circuit resistance is negligable) and it has a capacitance of 18.0μf or 18.0x10^-6f, therefore charge equals (18.0x10^-6)x12=2.16x10^-4C (Coulombs).