Download Friction Lab

Name: ________________________________________________ Period: _______ Date: _______________
Friction Lab
Part 1: Use the force sensor to determine how roughness of surface
affects the amount of static and kinetic friction. Static friction is
the force of friction on the object when it is not moving. Kinetic
friction is the friction on the object as the object is moving.
Set the graph options to manual and range from 0 N to 7 N
and up to 6 seconds. Set the data collection to 6 seconds as
well.
Part 1 Data: One weight
Sandpaper
Foam rubber
Cork
Cardboard
Lab table surface
Cardboard
Lab table surface
Cardboard
Lab table surface
Static Friction (N)
Kinetic Friction (N)
Part 2: Use the force sensor to determine how surface area affects friction.
Turn the block on its side to decrease the surface area and measure
the static and kinetic friction of each surface. This is how the lab set
up will look for part 2. 
Part 2 Data: Lower surface area
Sandpaper
Foam rubber
Cork
Static Friction (N)
Kinetic Friction (N)
Part 3: Use the force sensor to determine how weight affects
friction. Use two weights to increase the weight and
measure the static and kinetic friction of each surface.
This is how the lab set up will look for part 3. 
Part 3 Data: More weight
Sandpaper
Static Friction (N)
Kinetic Friction (N)
Foam rubber
Cork
Analysis Questions: Answer in complete sentences wherever necessary.
1) Roughness of surfaces affects friction. Rank the surfaces from greatest to least friction.
Greatest static friction:
Greatest kinetic friction:
Second most static friction:
Second most kinetic friction:
Third most static friction:
Third most kinetic friction:
Fourth most static friction:
Fourth most kinetic friction:
Least static friction:
Least kinetic friction:
2) How does surface area affect friction? Use specific examples from your data.
3) How does weight affect friction? Use specific examples from your data.
4) Which type of friction (static or kinetic) always seems to be greater? Why do you think this is?
5) Friction can be beneficial or detrimental. Give an example of when you want there to be friction, AND give an
example of when you would want to minimize friction.
6) Your friend has just tried on a ring and now cannot get it off her finger. She pulls and pulls and it just won’t come
off. Why won’t the ring come off, AND what could your friend do to get the ring off. Use the term “friction” in
your answer.
7) Draw a free body diagram for the following example:




Wood block pushed to the right across a flat surface
Weight (Fg) = 12 N*
Force of friction (Ff) = 5 N
Pushing force (FP) = 8 N
Net force = __________ to the ___________
* Don’t forget to include the normal force (FN)