A computer and monitor use 800J of electric energy each second. The monitor produces 30J of light energy each second. The fan in the computer converts 15J each second into kinetic energy. The lights on the tower give off 10J of light energy. If all the remaining energy is converted into heat, what percentage of the initial electric energy was converted into useful forms (as opposed to heat)?
I will be happy to critique your work.
Well, well, well! It seems we have a case of energy conversion here. Let's break it down, shall we?
We start with 800J of electric energy being consumed by the computer and monitor each second. Out of that, the monitor produces 30J of light energy, and the fan converts 15J into kinetic energy. The lights on the tower add another 10J of light energy.
So, the total useful energy produced is 30J (monitor) + 15J (fan) + 10J (tower lights) = 55J.
To find the percentage of useful energy, we need to compare it to the initial electric energy of 800J.
Percentage of useful energy = (55J / 800J) * 100%
Grabbing my handy-dandy calculator... *tap tap tap*
Drumroll please...
It turns out that the useful energy accounts for approximately 6.875% of the initial electric energy!
So, there you have it! A small fraction of the electric energy was converted into useful forms, while the remaining part decided to embrace the cozy world of heat.
To find the percentage of the initial electric energy that was converted into useful forms, we need to determine the total amount of useful energy produced and the total initial electric energy.
Given that the monitor produces 30J of light energy per second and the fan in the computer converts 15J per second into kinetic energy, we can calculate the total amount of useful energy produced per second:
Total useful energy = light energy from monitor + kinetic energy from fan
Total useful energy = 30J + 15J
Total useful energy = 45J
Furthermore, we know that the lights on the tower give off an additional 10J of light energy.
Total useful energy = Total useful energy + light energy from tower lights
Total useful energy = 45J + 10J
Total useful energy = 55J
Now, let's find the total initial electric energy consumed. It is given that both the computer and monitor use 800J of electric energy each second.
Total initial electric energy consumed = electric energy used by computer + electric energy used by monitor
Total initial electric energy consumed = 800J + 800J
Total initial electric energy consumed = 1600J
Finally, to calculate the percentage of the initial electric energy that was converted into useful forms, we can divide the total useful energy by the total initial electric energy and multiply it by 100:
Percentage = (Total useful energy / Total initial electric energy) * 100
Percentage = (55J / 1600J) * 100
Percentage = 0.034375 * 100
Percentage = 3.4375%
Therefore, approximately 3.44% of the initial electric energy was converted into useful forms (as opposed to heat).