Hi everyone, I'm new to forum and am a 3rd year university student who has never taken physics until now.. I'm currently studying for a dynamics unit test and came upon this question.... 1. The problem statement, all variables and given/known data A car whose brakes are locked skids to a stop in 70m from an initial velocity of 22.22m/s. Find the coefficient of kinetic friction. Vi: 22.22m/s Vf: 0m/s d: 70m a(deceleration): -3.526m/s^2 g= 9.81m/s^2 μ=? 2. Relevant equations - Found deceleration using kinematics formula Vf^2=Vi^2 =2ad - Ff= μFn - Fg=mg - Fnet(y)=ma ; a(up/down)=0 ; Fnet(y)=0 ; Fn-Fg=0 ; Fn=Fg 3. The attempt at a solution In order to find Fn, in order to be able to solve for μ, I need to know the mass of the car... I have no idea where to even begin solving for the mass of the car using the currently known values :( If anyone has time, please point me in the right direction.