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The Experiment
The next day, the girls stayed after school to do their experiment. They
had a new synthetic sponge and a new natural sponge. But there was a
problem. The natural sponge was much larger than the synthetic one.
Teasha and Kim decided to cut three small samples from each sponge.
The small samples would all be the same shape and same
mass
. They
cut and trimmed and
weighed
carefully. Finally, all six samples were
exactly 5 g.
“How should we soak the sponges to make sure it is a fair experiment?”
asked Kim.
“I know,” said Teasha. “We can use a stopwatch to time 1 minute
while we hold the sponges under water. That will really soak the sponges.
Then we’ll take them out of the water. We will hold them over the basin
for 30 seconds. Then we will weigh them to find out how much water
soaked into each sponge.”
“That sounds good to me,” agreed Kim. “Let’s get started.”
The girls soaked and weighed the first synthetic sponge. They repeated
the procedure with the other two synthetic sponges. They did this to make
sure their measurements were accurate. Then they did the same thing with
the three natural sponges. They recorded their measurements in a table.
The girls soaked the sponges
for 1 minute.
Then they let the sponges drip for
30 seconds.
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