To answer this question, we need to use a combination of physics and chemistry concepts. First, let's start with the physics aspect of the question. Watts and volts are both units of power, with watts representing the rate at which energy is used and volts representing the amount of electric potential energy per unit charge. We can use the equation P = IV, where P is power, I is current (measured in amps), and V is voltage, to calculate the amount of power needed to run the light bulb.
In this case, we know that the light bulb needs 100W of power and 120V of voltage. So, using the equation, we can calculate the current needed to power the light bulb as I = P/V = 100W/120V = 0.8333 amps.
Now, let's move on to the chemistry aspect of the question. We are given the mass of a copper penny, which we can use to calculate the number of electrons it contains. Copper has an atomic mass of 63.5 g/mol and a molar mass of 6.022 x 10^23 electrons/mol. So, a 5.0g penny would contain approximately 4.68 x 10^21 electrons.
Next, we need to calculate the total charge of these electrons. Each electron has a charge of 1.6 x 10^-19 coulombs. So, the total charge in the penny would be 4.68 x 10^21 electrons x 1.6 x 10^-19 C/electron = 7.488 x 10^2 C.
Finally, we can use the equation Q = It, where Q is charge, I is current, and t is time, to calculate the time the light bulb could run using the charge in the penny. Plugging in the values we have calculated, we get t = Q/I = 7.488 x 10^2 C/0.8333 A = 898.6 seconds.
Therefore, using all the electrons in a copper penny, we could run the 100W light bulb for approximately 15 minutes (898.6 seconds) before depleting the charge in the penny. It is important to note that this is just a theoretical calculation and in reality, there would be losses in the transfer of energy, so the actual time may be slightly different.
