Question

javier put two cups of tea on a table. the amount of tea in each cup was the same, but one cup was black and one cup was white. this table shows how the temperature of each cup of tea changed over 12 minutes.
cup of tea | initial temperature (°c) | final temperature (°c)
tea in the black cup | 89 | 73
tea in the white cup | 88 | 72
the next time javier drinks tea, he does not want it to cool down quickly. what should he do to minimize the rate of thermal energy transfer out of the cup of tea?
put the tea in the black cup
put the tea in the white cup
either; the rate of thermal energy transfer is the same whether the cup is white or black

Explanation:

Black surfaces are better at emitting (and absorbing) thermal radiation compared to white surfaces. In 12 minutes, the black - cup tea cooled from 89°C to 73°C (a drop of 16°C), while the white - cup tea cooled from 88°C to 72°C (a drop of 16°C). But considering the general property of black surfaces being more efficient in heat transfer, to minimize heat loss, a white cup should be used as it will transfer heat out of the tea more slowly.

Answer:

put the tea in the white cup