Question

A fast-food item contains $544$ nutritional calories. How do you convert this energy to joules?

Answer 1

A calorie is a unit of energy. It is defined as the amount of heat needed to raise a quantity of water by one degree of temperature. There are two versions of the unit. The small calorie which is denoted by '' $c$ '' and it is defined as the amount of heat energy needed to raise the temperature of one gram of water by one degree Celsius.

Nowadays, it is widely used in nutrition as the large Calorie which is denoted by '' $C$ '' and it is defined as the amount of heat needed to raise the temperature for one kilogram of water by one degree Celsius.
i.e., $1{\text{ }}C{\text{ }} = {\text{ }}1Kc$ .

Complete Answer:
We need to convert the calories into joules;
Therefore, One calorie is equal to the $4.184{\text{ }}Joules$ .
So, one kilocalorie will be;
$1\,kilocalorie\, = \,1000\, \times \,4.184\,Joules$ $= \,4184\,Joules$
Now, the given value is $544$ nutritional calories,
So, we need to convert the calories into joules;
Therefore, $554\, \times \,4184\, = 2317936\,Joules$ $= \,2.32\, \times \,{10^6}\,Joules$

A fast-food contains $544$ nutritional calories which are equal to $2.32\, \times \,{10^6}$ Joules.

Note: In nutrition, calories refer to the energy that people get from the food and drink they consume, and the energy they use in physical activity. Calories are listed on the nutrition information on all food packages. It is very important to know that the nutritional calories are always denoted in the form of kilocalorie due to large calories.

Calories in food provide energy in the form of heat by which our body can function. Human body stores and burns calories as fuel. The food we eat converts the fuel by which our body gets functioned. Eating healthy provides calories (energy) and essential nutrients to build strong bones and muscles. Beverages also contain calories. But not all calories are healthy. Soft drinks, for example, are often called "empty calories." That means they provide calories but have no other nutritional value.