• To practice the skills To practice the skills used in scientific used in scientific investigationsinvestigations

• To think like a scientistTo think like a scientist

• Many brands of paper Many brands of paper towels claim to be the towels claim to be the best. best.

• Which brand of paper Which brand of paper towel is the best?towel is the best?

• In research laboratories, In research laboratories, papermakers test the paper papermakers test the paper they make for physical they make for physical properties such as properties such as strength, strength, absorbencyabsorbency, stretch, tear , stretch, tear resistance, folding endurance, resistance, folding endurance, and stiffness. They also test and stiffness. They also test for optical properties like for optical properties like transparency, opacity, transparency, opacity, brightness, color, and gloss.brightness, color, and gloss.

• Since paper towels are usually Since paper towels are usually wet when they are being used, wet when they are being used, the “absorbency” and “wet the “absorbency” and “wet strength” of the towel is strength” of the towel is important. important.

• AbsorbancyAbsorbancy is the towels is the towels ability to hold water. This can ability to hold water. This can be measured by how much be measured by how much water the towel can hold.water the towel can hold.

• Wet strengthWet strength is the strength of is the strength of paper when wet. This can be paper when wet. This can be measured by the amount of measured by the amount of mass that a wet paper towel mass that a wet paper towel can hold.can hold.

• If_____ is the strongest If_____ is the strongest paper towel, then it will paper towel, then it will hold the most weight.hold the most weight.

• If_____ is the most If_____ is the most absorbant paper towel, absorbant paper towel, then it will hold the most then it will hold the most water.water.

(Bounty, Scott, Generic, Tops)(Bounty, Scott, Generic, Tops)

Gather materials:Gather materials:• 4 brands of paper towels4 brands of paper towels• Graduated cylinderGraduated cylinder• 2 jars with ring lid2 jars with ring lid• Pennies or weightsPennies or weights• WaterWater• Triple beam balanceTriple beam balance

Variable GridVariable Grid• Independent Variable:Independent Variable:

• Dependent Variable:Dependent Variable:

• Controlled Variables:Controlled Variables:

• Step by step process to Step by step process to followfollow

• Number the stepsNumber the steps• Use complete sentences.Use complete sentences.• Be specific!Be specific!

1.1.

2.2.

3.3.

4.4.

5.5.

6.6.

1.1.

2.2.

3.3.

4.4.

5.5.

6.6.

• Chart including trials and Chart including trials and reduced data (averages)reduced data (averages)

• Graph of reduced dataGraph of reduced data• Remember to label X and Y Remember to label X and Y

axis and give a specific title axis and give a specific title that relates to the purpose that relates to the purpose of the labof the lab

TowelTowel #pennies#pennies

Mass (g)Mass (g)#pennies#pennies

Mass (g)Mass (g)#pennies#pennies

Mass (g)Mass (g)#pennies#pennies

Mass (g)Mass (g)

Trial 1Trial 1 Trial 2Trial 2 Trial 3Trial 3 TotalTotalAverageAverage

BrawnyBrawny ## ## ## ## ##

gg gg gg gg

ScottScott ## ## ## ##

gg gg gg gg

GenericGeneric # # ## ## ##

gg gg gg gg gg

TowelTowel Volume Volume (ml)(ml)

Volume Volume (ml)(ml)

Volume Volume (ml)(ml)

Volume Volume (ml)(ml)

Trial 1Trial 1 Trial 2Trial 2 Trial 3Trial 3 TotalTotalAverageAverage

BrawnyBrawny ## ## ## ## ##

gg gg gg gg

ScottScott ## ## ## ##

gg gg gg gg

GenericGeneric # # ## ## ##

gg gg gg gg gg

00.10.20.30.40.50.60.70.80.9

1

label

Bounty Brawny Generic

label

Title

First paragraph (5 sentences)First paragraph (5 sentences)•Restate the hypothesis.Restate the hypothesis.•Do you accept or reject your Do you accept or reject your

hypothesis?hypothesis?•Give 3 facts from your data Give 3 facts from your data

that support the hypothesis. that support the hypothesis. Look at your chart/graph.Look at your chart/graph.

• In conclusion, ___.In conclusion, ___.

Second paragraph (5 sentences)Second paragraph (5 sentences)• How would you change this How would you change this

experiment if you repeated it?experiment if you repeated it?• How can this information be How can this information be

used? used? • Is it helpful information for Is it helpful information for

individuals or society?individuals or society?• Who cares about the results?Who cares about the results?