What is different between calories and joules?

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  • Zirp
    Lv 7
    4 months ago

    Calorie is defined as the amount of energy needed to heat up a gram of water one degree celsius

    Joule is defined as amount of energy needed to speed up a gram by one meter per second,  or as watt times second

    Ultimately it's very much like comparing a liter to a gallon

  • 1 Joule = 1 Newton * 1 meter.

    Joules measure the amount of work that is done to move a mass through a space.  If you move a 1 kg object on the Earth's surface (or more accurately, it's accelerating downward at an acceleration of g) a distance of 1 meter, then you'll use 1 Joule of energy to do so.

    1 Calorie is the amount of heat energy it takes to raise the temperature of 1 gram of water by 1 degree Celsius.

    4.186 Joules = 1 Calorie

    They both measure energy, which is why they convert easily, but the way they are defined is slightly different.

  • ?
    Lv 7
    4 months ago

    note that food calories are actually 1000x these calories. 

    1 cal = energy needed to raise the temperature of 1 gram of water by 1° centigrade. 

  • 4 months ago

    joules are the standard SI (metric) unit of energy

    calories are an obsolete unit of energy, from the old cgs system

    1 joule is equal to:

    0.2390 cal (gram calories)

    2.390×10^−4 kcal (food calories)

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