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Intro to Temperature & Heat

• All atoms and molecules have some vibrational motion in them, even solid objects. We call the average of this motion in a substance temperature (T).
• Since temperature is based on motion, the lower limit of this is when the objects stop moving: this is called absolute zero.
• We measure temperature in kelvin (K). Absolute zero is 0K. One kelvin is the same "size" as a Celsius degree, but they have very different starting points. We can convert between them with
  

  TC = TK − 273.15.

• Heat (Q) is the transfer of thermal energy. Heat is positive when the environment puts thermal energy into the system, and negative when the environment takes energy out.
• One calorie (cal) is the amount of heat required to raise one gram of room temperature water by one kelvin/one degree Celsius.
• Since thermal energy is a form of energy, we can covert calories to joules:
  

  1  cal = 4.1868 J.

• Different materials take different amounts of heat to have the same change in temperature. The specific heat (c) of an object tells us the proportion of heat to temperature change. Different substances have different specific heats.
• The more mass an object has, the more thermal energy it takes to increase its temperature. In general, the amount of heat required for a change in temperature is
  

  Q = cm(∆T).