2. I don’t think that all the energy from the burning food went into heating the water. Some of it also heated the test tube and the air around it. Not all of the energy went into the heat; also some went into the light of the fire.
3. One of the major difficulties in doing this experiment was lighting the pieces of food and placing it quickly under the tube without losing energy on the way (due to burning). We didn’t want all the energy to go to the fire, because then we would not have the correct result. I don’t see any easy solution to this, apart from practicing.
4. Foods from most energy to least
Popcorn (542 cal),
Mars Bar (448 cal),
Rice Bubbles (382 cal),
Pasta, cooked plain (132 cal).
Foods with more calories give off more energy.
Conclusion
Out of the three foods investigated, the one with the most energy was the Tiny Teddies (3276j), followed by Cheezels (2940j) and finally the Nutrigrain (504j). My original hypothesis was that the Cheezels had the most energy, because I thought they had the most calories. Given the results, I have to conclude that Tiny Teddies had most calories.