Do
you know why some houses have tin roofs or some painted black? Why do
outdoor athletes mainly were bright colours while performing/practising (white,
cream, yellow)? The fact is that some colours tend to absorb more
heat than others. Scientific experiments have proven that dark surfaces
tend to absorb more light while shiny, bright surfaces reflect the heat
energy. Why not try out this small experiment to see if this is
true?
Materials Needed : 2 identical jars filled with equal
amounts of cold water
1 sheet of black paper and 1 sheet of shiny, foil paper
2 thermometers
Light Source (Eg. Small Lamp)
| Procedure :
Fill equal quantities of slightly cold water into the 2 jars and
cover one of them with the black paper, and the other with the
shiny paper (as shown in the diagram). Label the jars (A
- black and B-foil) as well as the thermometers and
record the temperatures. Place both the jars at the same
distance from a light source (a lamp, tubelight etc.)
and after an hour, re-check the temperatures. You will see that
the water temperature in A will increase while that in B
remains relatively the same. |
 |
How did this
happen?
Dark surfaces absorb more heat and so the black paper absorbs
heat and transmits the heat to the jar and water. Heat energy that falls
on the shiny foil paper bounces back, therefore unaffecting the water
temperature.
NOTE: The light source should be placed close to the jars
otherwise the results will not be satisfactory. A single thermometer can
be used but the readings may not be highly accurate since you will have to
wait for the mercury to reach normal temperature before using it again,
and this may be time-consuming.
So next time you
are going out to play or going on vacation, make sure you wear the right
colour clothes!
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