c = 0.182772277 cal/g * C
What type of substance is it? it's not glass.
Do you have a chart of common substances and their specific heats? If not, I'm sure you could find one on the internet. If the specific heats listed are in different units use the conversion factor 4.184Joules/Calorie.
My table only has 0.18 for Glass. And I know is not glass.
actually it probably is given the general acceptance of the idea of approximate input giving apporximate output, which is is used as an excuse by lazy text book writers to give what they consider to be a "significant" number of digits. Basically except for those of us (like me) who are the most anal about precision .18 and .182772277 are the same.
A good table of such values will display the uncertianity in the given values. To use digits beyond the given known errors is to introduce garbage in your calculations. If a number is given to 2 or 3 digits, simply assume that the error is .5 of the first unspecified digit.
Any experimentally computed value should include an error analysis of the measurements required to complete the computation.
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