13.5. Specific Heat http://www.ck12.org
13.5 Specific Heat
Objective
The student will:
- Solve problems involving specific heat.
Vocabulary
- specific heat:The amount of heat required to raise the temperature of one gram of a substance by one Celsius
degree.
Specific Heat
We know that when we heat an object, its temperature increases. But a given quantity of heat will not produce the
same temperature change for every object. Recall that it requires 4.186 J of energy to raise the temperature of one
gram of water by one degree Celsius. It can be determined experimentally that the same 4.186 J, if transferred to
one gram of copper, will raise its temperature by 10.7 degrees Celsius.
For a given mass, experiments show that the temperature rise due to a fixed amount of energy transfer depends upon
the material heated. Thespecific heatcof a material is the amount of energy needed to raise the temperature of one
kilogram of a particular substance by one-degree Celsius. The change in temperature∆Tof an object depends upon
the amount of massmof the object being heated, the specific heatcof the material the object is composed of, and
the amount of energy∆Qtransferred to the object. It can be shown experimentally that:
∆T=∆mcQ→∆Q=mc∆T
The SI units of specific heat arekgJ◦C.
TheTable13.1 gives specific heat values for some common materials.
TABLE13.1:
Substance Specific heat(
J
kg◦C)
at standard atmospheric pressure
and at 20°C
Liquid Water 4,186
Wood 1,700
Glass 840
Zinc 390
Copper 390
Silver 230