A 55.6 kg boulder sat on the side of mountain beside a lake. The boulder was 14.6m above the surface of lake. One winter night, the boulder rolled down the mountain, directly into a 204 kg ice-fishing shack that was on a frozen lake. What was the velovity of the boulder and the shack at the instant that they began to slide across the ice? If the coefficient of friction between shack and rough ice is 0.392, how far did the shack and boulder slide? :uhh: Ok I figured that m1v1 + m2v2= v' (m1 + m2) then mgh = 0.5mv^2 (55.6*9.8*14.6) = 0.5*(204+55.6)v^2 I don't know why they are giving us friction for. Someone please help soon. I have test tommorow!