Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
Lab #1:  - Shoe Lab
Purpose:
 Determine the relationship between normal force and applied force
 Determine the coefficient of friction between a shoe and different surfaces
 Answer the questions:
o How does mass impact the coefficient of friction between an object and a surface?
o How does the type of surface impact the coefficient of friction between an object and a surface?
Materials:
 shoes
 spring scale
 set of masses
 lab table
 rubber surface or back of whiteboard
 pencil
 lab sheets with data tables
Lab Safety
 Use only the materials given at the lab station. Use materials for their intended purpose only.
o Set of masses – used to add mass to the shoe
o Spring scale – hook to the back of the shoe
o Rubber surface or back of whiteboard – remains flat on the lab table, used as a resting surface for the shoe
 No protective equipment necessary.
Procedure:
1. Write down your hypothesis under the “Hypothesis” section of the lab report.
2. Place your shoe flat on the lab table, sole down.
3. Sketch the setup of the experiment and label the free body diagram.
4. Determine the normal force of your shoe using the spring scale. Record the normal force in Data Table 1 for “shoe.”
5. Attach the force meter to the shoe and, holding the force meter horizontally, pull the shoe across the desk. Measure the
force required to just start the movement of the shoe. It may take a few tries until the team can get an accurate reading.
Repeat a few times until the team gets the same result multiple times, then record the reading in Data Table 1 under
“Applied Force”.
6. Repeat steps 4 and 5 for trials 2 - 5, adding more mass to the shoe as specified in Data Table 1.
7. Repeat steps 4, 5 and 6 using the second surface at your table.
8. Using the data from Data Table 1, plot the applied force vs. the normal force in Figure 1. Draw a line of best fit, and
determine the slope of that line.
9. Using the data from Data Table 2, plot the applied force vs. the normal force in Figure 2. Draw a line of best fit, and
determine the slope of that line.
1
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
Lab Report
Group Members:
 Data Logger: ________________________________________________________
 Data Recorder: ______________________________________________________
 Materials Manager: ___________________________________________________
 Operations Leader: ___________________________________________________
Purpose:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Hypothesis:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Experimental setup and free body diagram:
2
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Part 1
Shoe: ___________________________________
Surface: _________________________________
Data
Trial
1
Object
Shoe
Normal Force (N)
2
Shoe with 50 g
3
Shoe with 100 g
4
Shoe with 200 g
5
Shoe with ____ g
(your choice)
Applied Force (N)
Data Table 1 – Group Data for Surface 1
Figure 1 – Graph of Normal Force v. Applied Force for Data Set 1
Slope of the best fit line in Figure 1 (include units):
3
Team:
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Part 2
Shoe: ___________________________________
Surface: _________________________________
Data
Trial
1
Object
Shoe
Normal Force (N)
2
Shoe with 50 g
3
Shoe with 100 g
4
Shoe with 200 g
5
Shoe with ____ g
(your choice)
Applied Force (N)
Data Table 2 – Group Data for Surface 2
Figure 2 – Graph of Normal Force v. Applied Force for Data Set 2
Slope of the best fit line in Figure 2 (include units):
4
Team:
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
CLASS DATA
Type of shoe
Coefficient of static friction on lab table
Group 5
Converse
Group 1
Green Aasics
Group 2
Group 6
Blue Aasics
Group 3
Group 7
Flip flop
Group 4
Group 8
Directions: Use complete sentences to answer the remaining questions.
Analysis:
1. In step 5 of the procedure, what does your applied force represent? ______________________________________
___________________________________________________________________________________________
2. What does the slope of the graph in Figures 1 & 2 represent? ___________________________________________
___________________________________________________________________________________________
3. What happened to the applied force when you increased the weight of the shoe? _____________________________
___________________________________________________________________________________________
a. Why did this happen? ___________________________________________________________________
___________________________________________________________________________________________
4. What happened to the coefficient of friction when you increased the weight of the shoe? ______________________
___________________________________________________________________________________________
a. Why did this happen? ___________________________________________________________________
___________________________________________________________________________________________
5. Was your hypothesis correct? ____________________________________________________________________
___________________________________________________________________________________________
Conclusions: How does mass impact the friction between an object and a surface? How does the type of surface impact the
coefficient of friction? Support your decision with data.
5
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
Critical Thinking and Application Questions:
1. **Propose at least 3 ways to reduce the amount of friction.
2. What does it mean for one shoe to have a higher coefficient of friction?
3. *Why is it helpful for shoes to have friction?
4. What athletes would want low coefficients of friction on their feet?
5. **Do you think a basketball shoe or a ballet shoe should have a higher coefficient of static friction when a horizontal
force is applied to it on the floor? Why?
6
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
6. **What sources of error were there in this experiment? In other words, what are some possible ways that you could
have recorded incorrect data or data that was not entirely accurate?
7. **If you could repeat this experiment, what could you do differently to limit the sources of error?
7
Engineer/Scientist:
Lab #1: μ-Shoe Lab
GROUP #
Date:
Education is Freedom!
Team:
/24
RUBRIC FOR ASSESSING LAB REPORTS
4
Exemplary
Hypothesis
Results:
data, figures,
graphs, tables,
etc.
Addresses the question and
strongly supports the idea with
advanced scientific knowledge
The graphs and tables are
correctly drawn or computer
generated
Conclusions
All important conclusions have
been clearly made, student
shows good understanding
Critical
Thinking
Makes advanced connections to
scientific concepts and explains
improvements in great detail
with strong support
Spelling,
grammar,
sentence
structure
Over-all
Appearance
and
Presentation
All grammar/spelling is correct
and very well-written.
Over-all presentation of entire
assignment is professional,
extremely neat and organized.
Written parts are typed or
written very neatly.
3
Accomplished
Addresses the question and
provides adequate support
based on knowledge of science
The graphs and tables are
correctly drawn or computer
generated, but some have minor
problems or could still be
improved
All important conclusions have
been drawn, but could be better
stated
Makes connections to concepts
beyond the scope of the lab,
identifies ways to improve the
experiment and provides strong
support for these ideas
Less than 3 grammar/spelling
errors, professional, readable
style
Writing is legible and can be
read clearly. Drawings and
graphs are professional and only
minor improvements are
needed. Work is organized.
2
Developing
1
Beginning or incomplete
Addresses the question, but
provides little support and/or
reasoning
Most figures, graphs, tables
drawn, some still missing
important or required features
Does not address the objective
or question posed
Conclusions regarding major
points are drawn, but many are
misstated, indicating a lack of
understanding
Demonstrates limited ability to
make connections beyond the
lab, identifies simple ways to
improve the experiment without
great detail
Occasional grammar/spelling
errors, generally readable, some
parts of writing style may be
poor or unprofessional
Conclusions missing or missing
the important points
All writing is legible, but some
parts are hard to read.
Drawings and graphs are legible,
but improvements are needed to
make it professional. Work is
reasonably organized.
Sloppy, illegible writing
throughout, drawings and
graphs are difficult to read,
unprofessional. Work is not
organized
8
Figures, graphs, tables contain
errors or are poorly constructed,
have missing titles, or numbers,
units missing or incorrect, etc.
Does not demonstrate ability to
make connections, does not
identify ways to improve the
experiment in the future
Frequent grammar and/or
spelling errors, writing style is
poor and/or unprofessional
Comments:
Score