Two identical water cans stand in the sun. One is dull black, the other shiny silver. Which warms faster?
AThe shiny silver can
BBoth warm equally
CNeither can warms
DThe dull black can
Answer & Solution
Correct answer: D. The dull black can
1. Radiant energy landing on a surface is either absorbed or reflected.
2. Dark, dull surfaces absorb most of the energy that reaches them.
3. Light, shiny surfaces reflect most of it away instead.
4. The dull black can therefore takes in more energy each second.
5. More energy taken in means its water warms faster.
6. Both cans do warm in the end, but not at the same rate.
_Source: Siyavula Natural Sciences Grade 7 (CC BY 4.0), Which surfaces absorb the most radiation?_