The Coefficient of Static Friction Test

Contributors: Nicholas Ettinger & Benjamin DeJonge



  • To determine the coefficient of static friction between an Oreo and various surfaces.


  • Oreo Cookies
  • Random surfaces
  • Protractor


  1. Place an Oreo on a flat surface of interest.
  2. Slowly incline the surface above the horizontal just until the Oreo starts to slide.
  3. Quickly back the surface back down to a more shallow angle until the Oreo is seen to slide at a constant speed down the incline.
  4. The coefficient of static friction can be calculated µs = tan (θ)


  • Data table 1 shows the "critical angle" recorded for each trial of various materials.
    Material Trial 1 Trial 2 Trial 3 Average
    Styrofoam 21 ° 20 ° 24 ° 21.7 °
    Oak 19 ° 17 ° 18 ° 18 °
    Aluminium 28 ° 20 ° 25 ° 24.3 °
    Plastic 22 ° 23 ° 20 ° 21.7 °


  • Data table 2 shows the calculated coefficients of static friction based on the average critical angle measured from the trials.
    Material µs
    Styrofoam 0.39
    Oak 0.32
    Aluminium 0.45
    Plastic 0.39
  • From the results one can see that Styrofoam and Plastic (think veneer cover in a binder) have the same measured coefficient of static friction.
  • In order of increasing "stickiness" the materials are ranked oak, Styrofoam = plastic, aluminium.


  • Oreos are found everywhere, some would argue they are a nuisance. If one wanted to construct some sort of Oreo catching device the best material of those tested would be Aluminium. This would enable the metal to easily grab the Oreos and keep them in place.


 DISCLAIMER: The views and opinions expressed herein are in no way affiliated with the Albion Central School District or Nabisco in any way.