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Homework Help: The Energy Contained in a FunyunI must be mistaken?

  1. Sep 23, 2009 #1
    1. The problem statement, all variables and given/known data
    I'm required to find the amount of energy via calories in a single funyun and then calculate the amount of calories per gram.

    2. Relevant equations
    Q=(M)C(deltaT)(Energy gained)
    Q=M(deltaT) (Get Q in calories minus C because specific eat for water is same as joules per calory)
    Calories per gram = calories /mass of food/1000

    3. The attempt at a solution
    So I set up my home made Calorymeter(Had to make it) . So I lit it on fire and got managed to get a Delta Temperature. Then did Q=61gx(16.7) And got 1018.7Calories. But my problem is..Can a single Funyun contain 1000+ calories? Am I doing something wrong? I got 0.848 for calories per gram, which sounds reasonable..I may be right but I'm confused about this. Every funyun we eat contains 1k calories?..K i just multiplied 0.848 x 1.2 and got 1.0716 ..Does this have something to do with the bag having a Capital C for 1k calories and what not?
  2. jcsd
  3. Sep 23, 2009 #2
    Food labels have kilocalories on them. 1 Kcal = 1000 calories = 4.2 KJ.
    1 kcal for each funyun seems plausible, maybe even too low. Pure fat is about 9 kcal/g. Carbohydrates 4 kcal/g. Whats the weight of a funyun?

    You have 1018 Calories for each funyun, but .848 calories per gram. The second number must be kilocalories.
  4. Sep 24, 2009 #3
    I'm did not weigh the funyun. =/ However If those most a healthy person is to eat in a day is 2000-300o calories then how does can a 1018 calory funyun even be realistic?
  5. Sep 24, 2009 #4
    Of course those are 2000-3000 kilocalories as well. so if a funyn really has 1018 calories is 1.018 kilocalories, you could eat 2000 a day.
  6. Sep 24, 2009 #5


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    Were you actually instructed to find the calories this way? Could you not just read the Calories and weight info from the package?

    Also (as willem2 said) 1 food Calorie = 1000 calories

    Note the uppercase "C" is used for food Calories.
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