1. The problem statement, all variables and given/known data In class, we conducted a lab experiment in which we placed an object on the end of a piece of wood and lifted the same end of the wood until the object slid down to the bottom. We measured the height the wood was lifted to. (to assist in calculating Coefficient of Friction for kinetic force) We then repeated this step, and quickly brought the piece of wood down so as to stop the object from moving, and measured this height. (to assist in calculating Coefficient of Friction for static force) The length of the wood was measured (which would act as "r" or "radius" or "hypotenuse" in this case). We repeated the whole routine above for four additional different objects, for a total of five objects' values. The trouble I am having is a question asked of us as part of the lab questions, based on this experiment and the collected data. Q1: From the value of [tex]\theta[/tex] (which I calculated already), determine the coefficient of friction [tex]\mu[/tex] (static) and [tex]\mu[/tex] (dynamic), as indicated below: a) Draw the force diagram of a weight in equilibrium that is on the inclined plane. Set up the x and y axis parallel to the surface respect to the inclined plane. Then set up two equations from these forces from the equilibrium equations [tex]\Sigma[/tex]Fx = 0 [tex]\Sigma[/tex]Fy = 0 then solve for [tex]\mu[/tex] (coefficient of friction) b) Using the formulae derived in (a) above, solve for [tex]\mu[/tex]. 2. Relevant equations F = [tex]\mu[/tex]*N [tex]\mu[/tex] = F/N = m*g*sin[tex]\theta[/tex] / m*g*cos[tex]\theta[/tex] [tex]\mu[/tex] = sin[tex]\theta[/tex] / cos[tex]\theta[/tex] [tex]\mu[/tex] = tan [tex]\theta[/tex] 3. The attempt at a solution No attempt has yet been made, as I do not know where to begin, nor understand what I am being asked to do. I've read the textbook, which does not help me determine what to do... Do I take the sum of all 5 values for static and dynamic friction coefficients and determine an average [tex]\mu[/tex] ? Do I draw 5 force diagrams of a weight in equilibrium for each object, and then solve for [tex]\mu[/tex] by using specifically only the values pertaining to that one object? Am I going to subtract static friction force from dynamic friction force? Average them? And by "formulae derived" are they referring to something I have to derive myself from the given formulae, or the very same formulae they gave me (i.e.: did they derive the formulae for me already)?