Download Sticky Shoes Lab

Name:___________________________Date:_______CP:___
Problem: Friction is a force that acts in the opposite direction to motion.
Hypothesis: How can you create more friction between a shoe and the surface the shoe moves across?
Materials: Three or more different types of shoes, 2 spring scales (5 N and 20 N), marbles, batteries, tape,
large paper clips, scale
Explanation: Shoes are designed to deal with various frictional forces, including these:
a. Starting friction, which is involved when you start from a stopped position
b. Forward-stopping friction, which is involved when you come to a forward stop
c. Sideways-stopping friction, which is involved when you come to a sideways stop
Procedure:
1. Place each shoe you are testing on the scale. Then put masses in each shoe so that the total mass of the
shoe plus the masses inside is 1000 g (1 kg). Spread the masses out evenly inside the shoe.
2. Tape a paper clip to each shoe and then attach a spring scale to the paper clip. To test
a. starting friction, attach the paper clip to the back of the shoe
b. forward-stopping friction, attach the paper clip to the front of the shoe
c. sideways-stopping friction, attach the paper clip to the side of the shoe
3. To measure starting friction, pull the shoe backward until it starts to move. Use the 20 N scale first. If
the reading is less than 5 N, use a 5 N scale. The force necessary to make the shoe start moving is equal
to the friction force. Record the starting friction force in your data table.
4. To measure either type of stopping friction, use the spring scale to pull each shoe at a slow, constant
speed. Record the reading as the stopping friction in your data table.
Data:
Sideways-Stopping
Forward-Stopping
Type of Shoe
Starting Friction (N)
Friction (N)
Friction (N)
1.
2.
3.
4.
Analysis:
1. Controlling variables: What are the independent and dependent variables?
Independent:
Dependent:
2. Observing: Why is the reading on the spring scale equal to the friction force in each case?
Name:___________________________Date:_______CP:___
3. Interpreting Data:
Which shoe had the most starting friction?
Which had the most forward-stopping friction?
Which has the most sideways-stopping friction?
4. Drawing Conclusions:
Why did this activity require you to add mass to each shoe before testing the shoe’s friction?
Why did this activity require you to make the mass of EACH shoe equal to 1000 grams?
5. Inferring:
What do you observe that might cause one shoe to grip the floor better than another?
Why did you pull the shoe at a slow speed to test for stopping friction?
Why did you pull a shoe that wasn’t moving to test starting friction?
6. Developing Hypothesis:
What would be the purpose of a shoe having a strong starting-friction force?
What would be the purpose of a shoe having a strong a stopping-friction force?
What would be the purpose of a shoe having a strong side-friction force?
7. Extension: Choose ONE of the following to complete, then obtain printer paper from you teacher. When
finished staple your completed work to this lab, and turn it in.
Design and sketch a shoe for a specific sport. Explain why this shoe will be the best shoe for your
specific sport based on the shoe’s friction forces. Sketch and explanation must include at least 2
different types of friction force.
OR
Design an advertisement for a specific type of sport shoe. In your advertisement persuade people to buy
this shoe based on the shoe’s friction forces. Advertisement must include at least 2 different types of
friction force.