help for forth grade science project dealing with air, breathing or wind"
- J Contion (USA)
Purpose: The purpose of this experiment is to determine
the effects of blowing air on a drop of water. By doing so, this experiment
plans to determine what effect this will have on time it takes water to
Hypothesis: Based on scientific knowledge concerning
evaporation (which will be discussed in the conclusion) it is the
hypothesis of this experiment that the wind will cause the water to evaporate
quicker. Equipment: Needed for this experiment is a
medicine dropper, some water, a dish, stopwatch, and pen and paper.
Procedure: The first step is to take the medicine
dropper and place a small drop on the dish and start the timer. Record
the time it takes to completly evaporate. Next repeat the experiment, however,
this time, blow across the top of the water drop. Compare times.
Effects placed upon drop
Nothing done to water drop
1 hour 50 minutes 21 sec.
46 minutes 43 seconds
Conclusion: Based on the data, the hypothesis is
supported and water evaporates quicker with wind then without. The reason
for this is that for every liquid substance there is evaporation and condensation
occuring at all times. In other words, there are water molecules turning
from liquid to gas and other molecules turning from gas to a liquid. When
wind is present, molecules which normally would have turned from a gas
into a liquid are blown away from the liquid water source and are unable
to return. This leaves a situation where liquid molecules are turning into
gas molecules with no gas molecules turning back into liquid ones. Eventually,
the liquid water runs out. Because evaporation draws energy away to do
so, this becomes why we cool down by sweating, dogs are able to cool down
by panting and we can cool cups of hot chocolate down by blowing across
the top of it -- now how is that for a fourth grade science project? Here's some diagrams...