Conversion of 1335 kilo joules into Calories?

Answer 1

The mechanical equivalent of heat is 4.2 joules per calorie. Note the small c in calorie - this is the original, scientific unit of heat. It is defined as the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. Note also that the question wanted a conversion into Calories, with a capital C. This is the type of unit that is used for the energy content of food, although most cooks and nutritionists spell it with a small c. Scientists normally refer to it as a Kilo-calorie, which says exactly what it is, one thousand calories. This makes the question fairly easy to answer, because 4.2 joules/calorie translates straight into 4.2 kilojoules per Calorie. So, 1335KJ/4.2 gives 318 Calories.