Download DYN – Lab: Friction

Name: ______________________
Date: _______________________
DYN – Lab: Friction
Purpose:
1) To qualitatively study the effects of three variables (mass, surface area and
nature of materials) on the frictional forces between a friction block and a
wooden plank.
2) quantitatively determine the static and kinetic coefficients of friction between
three friction blocks with their respective emery coated-sides in contact with a
wooden plank.
Lab Report:
You will be graded on your ability to design a protocol to satisfy the purpose of this lab and
on your ability to reflect on your experiment and produce a formal laboratory report
communicating your findings. You will be instructed on the proper use of the dynamometer
to read the frictional forces (both static and kinetic). A digital camera will be available to
help you record the static frictional force, which is apparent only momentarily.
Your report should include:
- The purpose
- Your hypotheses
- The materials you used to perform the experiment.
- The procedure you developed and Implemented in this laboratory activity.
- The results you obtained (clearly tabulated) and relevant graph(s) {Note: a graph of
Ff (static and kinetic) vs. FN should be plotted for part 2. The slope of each of these
lines represent the coefficients of static and kinetic friction respectively}
- Any sample calculations.
- An analysis and discussion, which minimally should address the following:
o A summary of your results.
o A justification for procedural decisions.
o An analysis of the graphs, and explanation of trends.
o A comment about how the results support or refute the hypothesis.
o A link between your results and research (can include the textbook as a
reference). Include a discussion about the difference between static and
kinetic coefficients of friction, and a statement about when friction could be
considered helpful and when it is undesirable. If your hypothesis was refuted,
be sure to explain why based on your research. Remember to cite any
sources.
o An explanation of errors and suggestions for improvements.
- A conclusion.
o Includes a generalization of the results and an application of studying
coefficients of friction.
Due Date: Friday May 11th, 2012.