http://www.thephysicsaviary.com/Physics/Programs/Labs/ForceFriction/index.html   (link for experiment)

https://mech.subwiki.org/wiki/Angle_of_friction  (link for extra info)

How to write lab reports for my instructor:

Write the sections of your lab report in the following order.  For  instance it makes no sense to write an introduction paragraphs before  one knows how to write a summary of three other paragraphs.

General Principles:
A good theory section begins with  a discussion of the concepts and physical principles to be addressed in  this laboratory activity. The introduction then moves on to a  mathematical formulation of these same ideas and a derivation of the  actual formulas to be used in the activity. Consult you text on both  issues.  Shoot for a full page for this section. 
 

Methods:
 Broadly describe the conduct of the actual experiment. Specific details  should be limited to non-obvious tips for working with the  laboratory equipment or experimental simulation. A step by step lab  procedure, if available, should be referenced but not reproduced in this  section. In other words do not cut and paste the instructions. Have mercy on your grader!
 

Results:
Give the numerical result of your measurement along with an uncertainty.

Provide any supporting analysis with data tables, the calculations, graphs.

Tell me what you confirmed or did not confirm in this activity. If  you were to show that free fall acceleration is constant then  references your result and STATE whether or not your results support or  fail to support a constant value of free fall acceleration.  

Introduction:
Summarize the General Principles, Methods  and Results sections of the lab report.  A good rule of thumb is to  include one sentence per paragraph of the already written General  Principles, Methods, and Results sections of the lab report.  The aim  here is to summarize everything you have already written.

Conclusion:
Where the introduction was a preview of  the entire lab report, the conclusion is a review of the lab report. The  conclusion is also a summary, but where the introduction was forward  looking, the conclusion looks back on the same material.  Typically the  difference lies in word choices such as “We will show” as opposed to “we  have shown.”
 

References: Cite any references and  outside resources used in preparing this lab. At a minimum this should  include your class text and the PHET Colorado website if a simulation is  used.  Any commonly acceptable citation format is acceptable.  Just be  consistent.

Title Page and Abstract:
Use a standard heading  format in order to identify yourself, the class you are taking, and the  subject of the experiment. Below and on the same page, you will place  the abstract.  This is an 8 – 10 sentence summary of the entire lab and  is written in a manner that will intended to convince a reader to read  the rest of your report.  The form of this section is typically, “I did  _____ and then I proceeded to _____.  The result was a measured value of  _____, and from this I conclude  _______.”  An abstract is always written in italics.

Now assemble your lab report in the following order:

Page 1:  Title page with abstract.

Page 2 – 4:  Begin the body of your  report with the Introduction, General Principles, Methods, Results, and  finally the Conclusion.

Last Page :  Include references, all properly cited on the last page.

A grading rubric is included so that you can know how your work is going to be evaluated.