 Okay, so heat is the amount of energy you need to add to something to warm it up. But how do you actually calculate precisely how much energy is required? How many joules of heat or energy you need to change the temperature of something by, say, 10 degrees? Well, the way you work that out is by using a number known as the specific heat capacity. It's written with a letter C and it's defined as the amount of energy you need to add or subtract to 1 kilogram of some material to change its temperature by 1 Kelvin. If you write that down as an equation, the amount of energy you need to add or subtract is written as delta E. That triangle is a capital Greek letter delta and that means the change in the energy. So it's the amount of energy you're adding or subtracting. Now that is equal to the mass of the object in kilograms times the specific heat capacity times the change in temperature. And once again we're using that big triangle of the capital Greek letter delta to indicate the change in temperature. So the change in energy of a system equals the mass times the specific heat capacity times the change in temperature.