Measuring the Specific Heat of Metals by Cooling

Abstract

Three in one? Yes, three standard undergraduate thermodynamics experiments in one, not an oval can of lubricating oil. Previously it has been shown that the PASCO scientific1 apparatus for measuring coefficients of thermal expansion of metals can also be used to illustrate Newton's law of cooling in the same experiment.2 Now it will be shown that by cooling geometrically identical metallic samples and measuring their surface temperature change as a function of time, the specific heat of metals can be found by the method of comparison. This technique is simple to implement using the PASCO equipment for measuring the coefficients of thermal expansion of metals. A slight variation on this method was used in the Moscow State University students' laboratory for measuring temperature dependence of specific heat of copper over a large temperature range. As a result of this method, three experiments can be undertaken simultaneously to measure: 1) the coefficient of thermal expansion (α); 2) the time constant in Newton's law of cooling (H); and 3) the specific heatof metals (C).