My science homework is to collect 10 food labels which i have done and write down the food energy per 100g from each food in kilogrammes but the food labels i have have only got the energy in kj.
i`m cofussed because i don`t understand the question and i can`t ask my teacher because he is not in to ask. please help . thank you
There seems to have been a mistake in either the assigning or the copying of the problem. "Food energy per 100 g" should be stated in either kilogram-Calories or Joules or kilojoules.
1 kg-Calorie = 4184 Joules oe 4.184 kJ
In the USA, food labels state food energy in kg-Calories (although the kg is usually omitted) per "serving" size, and the mass or volume of a serving size is defined separately.
I can help you with that! To convert the energy value from kilojoules (kJ) to kilocalories (kcal), you can follow these steps:
1. Firstly, it's important to know that 1 kilocalorie (kcal) is equivalent to 4.184 kilojoules (kJ).
2. Look at the food labels and find the energy value in kilojoules.
3. Take the energy value in kilojoules and multiply it by 0.239 to convert it to kilocalories. This conversion factor (0.239) is derived by dividing the number of kilojoules (kJ) in 1 kilocalorie (kcal), which is 4.184, by 1000. (Note: The division by 1000 is necessary because you need to convert from 100g to 1g.)
4. Once you have converted the energy value from kilojoules to kilocalories, record it next to each food item on your list.
For example, let's say one food label indicates an energy value of 800 kJ. To convert it to kilocalories, you would multiply 800 by 0.239:
800 kJ * 0.239 = 191.2 kilocalories per 100g
So, for that particular food item, you would write down 191.2 kilocalories per 100g.
Repeat these steps for each food label you have, and you'll be able to convert the energy values from kilojoules to kilocalories.