How Much Friction?

Today we’re going to collect and analyze some data on the

amount of friction different surfaces have. We will use this

data to determine the most appropriate shoes to wear for different things students do.

You’re going to get some materials:

• a spring scale• some 1 inch tiles• a data collection chart

A spring scale looks like this:

You use it to measure the pulling force you apply to an object.

We are going to use the spring scales to measure the amount of force it takes to

pull our shoes across different surfaces in the

classroom!

We will also test the shoes to see if more force is

required to pull them when we add additional mass to

them by filling them with 40 1 inch tiles.

We are going to measure the amount of force we use

in a unit called

NewtonsDoes anyone have ANY idea

where this unit got its name?

First, let’s talk about how to read a spring scale. Our scales are

marked a bit like this:

ABOUT what measurement would be where the arrow is pointing?

2

6

4

N

0

4

2

N2

6

4

N

4

8

6

N6

10

8

N

0

4

2

N

Now you’re ready! Here’s how it will work:

• You will be in groups of two or three. (I will give you your groups.)

• You will remove 1 shoe! (No complaining about stinkiness!)

• You will share the spring scale with the members of your group to measure the amount of force required to pull your shoe across two surfaces.

Hypothesis: Which group member’s SHOES will require the most Newtons to pull? Why do you think so?

Which SURFACE will require the most Newtons to pull a shoe across? How do you know?

What will happen when you add mass to the shoes?

Name of Group Member: Style of Shoe: # of Newtons Required to Pull on Blue Carpet

# of Newtons Required to Pull on Tile Floor

no extra mass

+ extra mass

no extra mass

+ extra mass

Now! Decide group member and which surface required the MOST Newtons and circle the person’s name.Pick one group member to add the group member’s date whose shoe required the highest number of Newtons to pull to our class chart.

Class Data Collection for “How Much Friction?”Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7

Style of Shoe# of Newtons on Tile# of Newtons on Tile w/ mass added# of Newtons on carpet# of Newtons on carpetw/ mass added

What Does the Data Tell Us?