A jar placed in a sunny window..?

Question

Will it get warmest if wrapped loosely in

A. white cloth

B. black paper

C. wax paper

D. aluminum foil

Please help me I can't decide between B or D!!

Answer 1

The black paper will absorb the most solar energy as colors are the reflectance of light at certain wavelengths, with white being the reflectance of all the wavelengths.  The foil will reflect some of the energy, but metals hold thermal energy much better than paper I'd think.. but the question is whether or not the coupling of the paper to the jar and thus the efficiency of the transfer of heat energy allows it to heat the jar more so than the foil.  

Why don't you test it?  Take two equal jars filled with cold tap water of the same temperature and stick two thermometers in them.  Wrap foil around one, black paper around the other, put them in the same sunny spot and see what happens after 15 or 30 minutes.

Answer 2

B

Answer 3

I vote D  first  and B  second   *mamatx