A 60 watt light bulb in a household circuit at 120 V carries a current of 0.500 amp. (An amp was defined in class as a way to measure charge movement. One amp is one coulomb per second.) How many electrons move through this light bulb in five minutes?
To find the number of electrons that move through the light bulb in five minutes, we first need to calculate the total charge that passes through the light bulb.
Given:
Power (P) = 60 watts
Voltage (V) = 120 volts
Current (I) = 0.500 ampere
Time (t) = 5 minutes
First, let's convert the time to seconds:
5 minutes = 5 * 60 = 300 seconds
Next, we can calculate the charge using the formula:
Charge (Q) = Power (P) * Time (t)
Substituting the values:
Q = 60 watts * 300 seconds = 18000 joules
Since we know that 1 ampere is equal to 1 coulomb per second, we can find the number of coulombs of charge using the formula:
Charge (Q) = Current (I) * Time (t)
Substituting the values:
Q = 0.500 ampere * 300 seconds = 150 coulombs
Finally, we can calculate the number of electrons by using the charge of one electron, which is approximately 1.6 x 10^-19 coulombs.
Number of electrons = Charge (in coulombs) / Charge of one electron
Substituting the values:
Number of electrons = 150 coulombs / (1.6 x 10^-19 coulombs)
Now, let's calculate:
Number of electrons = 9.375 x 10^20 electrons
Therefore, approximately 9.375 x 10^20 electrons move through the light bulb in five minutes.