Measurement of Volume
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Richard Murray Gage Park High School
5630 South Rockwell
Chicago IL 60629
This mini teach is for middle school and high school students. It can be
adapted for younger children as a demo.
Students will be able to measure the volume of a clear container. Students will
be able to use a stop watch. Students will be able to estimate the volume of a
container using proportions.
Clear jars, glass or plastic, enough of them so that every group of students
will have two containers to measure. Enough sand to fill the largest container.
Measuring bowl and cup marked in milliliters; candles and matches; stop watches
for each group.
What was expected was a linear relationship between the burning of oxygen in the
jar and volume of air that it contained. If it is linear it will be
predictable. Knowing how long it takes to extinguish a candle for a certain
volume you should be able to predict either the volume and or the time to
extinguish a candle for another container.
The students will time how long a candle will stay lit when a jar is placed over
the candle. The student will measure the volume of the jar by filling it with
sand and using the measuring bowl or cup to find out how much sand is in the jar
in terms of the metric system.
Students will then time how long a candle will stay lit in a much larger
container. Knowing the previous data regarding volume and time and now knowing
the time for this new jar the student should now be able to predict the volume
of the second jar. The prediction is developed through proportions. The ratios
that make up the proportion are: volume is to time as second volume is to second
time. Restating the problem, the proportion will look like: volume in ml/time
to extinguish the candle = unknown volume of the new jar/time to extinguish the
Solving the proportion the student will have the predicted volume. To verify
the prediction the student will measure the volume of the second container using
sand. The student will determine how close the prediction is to the actual
The linear relationship that was expected was not produced by this procedure.
It was not established that there is linear relationship. The predictions for
the larger jar were off. If the time was measured for the larger jar then
predicted volume was larger then the actual measured volume. If the volume of
the larger container was measured then the predicted time differed greatly from
the actual time.
Sources of error are pressing the stop watch (timing errors), the candle is not
burning at a constant rate, a larger flame burns oxygen at a greater rate;
errors using the measurement bowl; the jars need time to refill with oxygen, if
you try to repeat the timing of the burning candle too soon the results will
vary as much as 4 to 5 seconds.
It was a good lesson in measuring, timing and gathering data. But it did not
support the hypothesis. Because the hypothesis is not supported then it creates
a problem for the students. The expectation is that the goal should be achieve
and it wasn't. This is a problem that will need to be addressed with the
Things that could be tried to improve the results are: work with larger volumes
such as storage cases instead of jars; the candle be replaced with a source that
burns consistently such as of oil with a wick.