For a personal project, I am analysing the physics in the Source video game engine and comparing it with real life. I have set up in the engine a platform which increases in inclination from 0 to around 70 degrees. On this platform there are four, equally weighted cubes each with a different material property: slime, ice, wood, and rubber. The weights of the cubes are modifiable and the angle of the platform is measurable. I have been told to use the coefficient of static friction equation. This is listed in "Physics" by Jim Breithaupt (1999, Macmillan Press, ISBN: 0333733028) as: μ = W sin theta / W cos theta Is this correct and relevant to my needs? Does this take into consideration the material properties of the blocks? How can I use the results in a meaningful manner? Additional: I have been told that this experiment can be used with the equations: sin theta * gravity * mass = pulling along force cos theta * gravity * mass = pulling down onto surface force Any explanation into this would be greatly appreciated, Kind regards, Danilo Vujevic.