Please Help Me..How do i calculate the energy content (in J/g AND calories/g)?

Question

For example i have the mass of each food sample burned and the heat energy gained in J and in calories

Answer 1

You say you are looking for the energy content of the food you tested in terms of Joules per gram and calories (notice the lower case "c") per gram. Calories, with a capital “C” indicates kilocalories, “kilo” meaning 1000. 1 Calorie = 1000 calories. Kilocalories (i.e. Calories) are also sometimes known as “dietary” calories as that is what is commonly referred to when taking about the energy content of food.

You are given the energy released from the food when combusted and you are also given the mass of the particular sample of food.

The units of the answer you are looking for should be a BIG clue as to how to solve this problem.

Joules and calories are units of energy.
A gram is a unit of mass.

To find the energy content per unit mass of a sample, divide the energy released from the sample by the mass of the sample.

Energy content per unit mass = energy released / mass
Both of these quantities (energy and mass) are known to you, so you should be able to plug in and solve for the energy content.

For example, lets say that you had a sample of food with a mass of 10 grams which, when burnt, released 1000 Joules of energy.
Energy content = 1000 Joules / 10 grams
Energy content = 100 Joules per gram

1 calorie equals 4.184 Joules,
1 Joule = .239 calories.
Using these conversion factors, you should be able to convert between the different units of energy you would like to use.

To convert calories to Joules, multiply by 4.184. To convert Joules to calories, divide by 4.184 (which has the same effect as multiplying by .239).

Answer 2

Aren't joules and calories terms for the same thing, i.e. energy? I mean like inches is the same thing as centimeters, a term for length.
I thought the conversion was 1 joule = 0.239005736 calories; unless it is stated as "C"alories which is usually meant to infer kilocalories, so that would be 1 joule = 0.000239005736 Calories.
hope this helps.