In our discussion of the concept of energy, it's important to remember that the SI unit for energy is Joule, and it's named after the English scientist James Jewell. When it comes to Jules, we're going to say that there are three particular types of conversion factors associated with it.
We're going to say here for the first one, we have 1 calorie, which is lower case C this equals 4.184 J. Next, we have one capital C calorie. This one is associated with food nutrition. This particular calorie equals 4184 J and then finally kilowatt hours. Usually when we talk about an electrical bill, it's associated with kilowatt hours. So we're going to say here kilowatt hours equals 3.6 × 106 J.
So these are three conversion factors associated with our SI unit for energy. Also realize here that I didn't put purple boxes around them, so usually you're not expected to memorize them. They're oftentimes given to you within the question, or they're given to you on a formula sheet when taking an exam. But here, just again, remember these are three common types of conversion factors associated with Joules.