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Homework Help: Energy required to heat different materials?

  1. Sep 21, 2011 #1
    Hello:) I am doing thermal physics at the moment, and am up to the part on specific heat capacity. I know that the equation Q=mc[itex]\Delta[/itex]T refers to the amount of energy required to raise the temperature by 1 degree celcius, but im just a bit confused about how the energy is calculated. For example, if i have a 10kg block of marble with specific heat capacity of 600, and i want to know how much energy is required to increase the temperature by 1 degree celcius, and i do: Q=(10)(600)(1), and my final answer is 6,000, is it in joules, because its energy? Also, if i want to know how much energy is required to DECREASE the temperature by 1 degree celcius, do i do Q=(10)(600)(-1)?
    thanks:):)
    1. The problem statement, all variables and given/known data



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  2. jcsd
  3. Sep 22, 2011 #2

    cepheid

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    Hi J-Girl,

    The specific heat capacity 'c' is defined as the energy needed to heat 1 g (or maybe 1 kg) of material by 1°C. As a result, it has dimensions of energy per unit mass and per unit temperature. This corresponds to units of J/(g°C) or J/(kg°C). You need to find out which of these two options are the units your stated c value of "600" is in.

    But, you can see that with these units, everything will work out as needed -- from the equation, Q will turn out to be in joules.
     
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