On the 18th of October, I had a physics lab about inclined plane, where we need to test all different materials to figure out the coefficient of friction.
There are seven objects which are five types of different sandpaper, cloth and wood. First of all we let the paper clip box on the wood and also the other six objects one at a time and see at which angle will the box start moving. We did three trials for one object and figure out the average angle. We use the average angle as ϴ (theta) to figure out for the coefficient of static friction. After that we just got to follow our equation which is F_g sin(ϴ) = μ*F_g cos(ϴ). Then this equation will become (F_g sin(ϴ))/(F_g cos(ϴ)) = μ. As F_g cancel out it will left sin(ϴ)/cos(ϴ) = μ, which is the same as tan(ϴ) = μ. Lastly we just replace the ϴ with the average angle and do the tangent of the angle and it will give the value of μ which we can also called as coefficient of friction. Then we just repeat the same thing to the other objects.