A hockey puck on a frozen pond with an initial speed of 12.3 m/s stops after sliding a distance of 198.9 m. Calculate the average value of the coefficient of kinetic friction between the puck and the ice. So I started with finding the acceleration. I divided 12.3m/s by 198.9m then took the inverse (so units would go back seconds) and came up with 16.17s. So now I have Δv and Δt so I divided 12.3m/s by 16.17s to get an acceleration of .76m/s^2 I also know that friction equals μN and that F=ma. Since N=mg and friction is the only force acting on the object, i divided the mass out. So I had μg=a, or μ=a/g. (using 9.81m/s^2 as gravity) So μ=.0774 which seemed reasonable for ice. But I dont know how to find the actual force without knowing the mass. Am I even heading in the right direction?