9SCIE - Energy for Life
When we are talking about food, energy is the chemical potential energy stored in the food. By eating the food we can break down the bonds in the food and gain energy!
You may hear energy referred to by calories.
1 calorie (C) is equal to \(4.2J\), or the amount of energy required to warm up \(1ml\) of water by degree C!
Look in your bag for some food in a wrapper with a nutritional label. How many Joules of energy does your snack contain? Make a note of it in your book.
Hint: kJ means kilojoules or 1,000J. So 120kJ means 120,000J.
It takes you approximately \(147J\) to jump \(0.3m\) off the ground. How many jumps do you have to do to burn off the energy from your snack?
In fact, we can find the amount of energy in a food in the lab! We will do this whakamātau later in this unit.
Before we start, recall that it takes \(1J\) to warm \(1ml\) of water by 1 degree C.