• To practice the skills used
in scientific investigations
• To think like a scientist
• Many brands of paper
towels claim to be the
strongest.
• Which brand of paper
towel is the strongest?
• In research laboratories,
papermakers test the paper they
make for physical properties
such as strength, absorbency,
stretch, tear resistance, folding
endurance, and stiffness. They
also test for optical properties
like transparency, opacity,
brightness, color, and gloss.
• Since paper towels are usually
wet when they are being used,
the “wet strength” of the
towel is important. Wet
strength is the strength of
paper when wet. This can be
measured by the amount of
mass that a wet paper towel
can hold.
• _____ is the strongest paper
towel.
(Bounty, Brawny,
Generic/school)
Gather materials:
• 3 brands of paper towels
• Graduated cylinder
• 2 jars with ring lid
• Pennies
• Water
• Triple beam balance
• Independent Variable:
• Dependent Variable:
• Controlled Variables:
• Step by step process to follow
• Number the steps
• Use complete sentences.
• Be specific!
1.
2.
3.
4.
5.
6.
1.
2.
3.
4.
5.
6.
• Chart including trials and
reduced data (averages)
• Graph of reduced data
• Remember to label X and Y
axis and give a specific title
that relates to the purpose of
the lab
Towel
#pennies #pennies #pennies #pennies
Mass (g) Mass (g) Mass (g) Mass (g)
Trial 1 Trial 2 Trial 3 Total
Brawny
#
#
g
Bounty
#
g
#
g
Generic
#
#
#
#
g
#
g
g
#
g
#
g
#
g
Average
g
#
g
g
g
Title
1
0.9
0.8
0.7
0.6
label 0.5
0.4
0.3
0.2
0.1
0
Bounty
Brawny
Generic
label
First paragraph (5 sentences)
• Restate the hypothesis.
• Do you accept or reject your
hypothesis?
• Give 3 facts from your data
that support the hypothesis.
Look at your chart/graph.
• In conclusion, ___.
Second paragraph (5 sentences)
• How would you change this
experiment if you repeated it?
• How can this information be
used?
• Is it helpful information for
individuals or society?
• Who cares about the results?