the unit that I find easiest to envision is the calorie.

The calorie is the amount of energy that it takes to warm up 1 gram

of water by 1 degree centigrade.

So a gram of water is about a milliliter, so

about a centimeter on each side, about the size of a plump raisin.

If you make that 1 degree warmer,

the amount of energy it took to do that is 1 calorie.

You see calories on the dietary labels of food.

And it's kind of a weird thing, dietary calories by convention mean kilocalories.

A kilocalorie is 1,000 calories.

So a factor of 1,000 there in your diet shouldn't throw you off too much, I hope.

And then the energy unit that we will use most in this class,

however, is joules and a joule is just 1 calorie is equal to 4.18 joules.

So a joule is just a constant times the calorie its like inches and centimeters,

their analogous, their the same dimension but they are different units.