1. The problem statement, all variables and given/known data please check this link out to make it simpler to understand... http://www.scribd.com/doc/62694749/MC-Collision1D2 there is a friction block and a spring scale... it gives two measurements (the vertical force and the horizontal force) Fvertical=88.2 N and Fhorizontal=75.8 N now i'm suppose to find the coefficient of friction... and also, i'm suppose to find out if the driver exceeded the 70 km/h speed limit please help me out! 2. Relevant equations m1vi1+m2vi2 = (m1+m2)vf KE=1/2(m)(v2) 3. The attempt at a solution for the mu: at first, i tried to use the "elementary" method of summation of forces along the axes but since we're talking about collisions, i think i should use the work-energy theorem... but now i don't know how to put mu into the equation: KE=1/2(m)(v2) ... for the speed limit: well, it's an inelastic collision obviously... one car is at rest but they didn't give out the vi1 of the yellow car... please help! i ran out of ideas on how to solve this!