1. The problem statement, all variables and given/known data A drunk driver strikes a parked car. During the collision the cars become entangled and skip to a stop together. The drunk driver's car has a total mass of 880 kg, and the parked car has a total mass of 804 kg. If the cars slide 39.5 m before coming to rest, how fast was the drunk driver going? The coefficient of sliding friction between the tires and the road is 0.37. 2. Relevant equations Δ(K + U) = Wnc 3. The attempt at a solution I am having some difficulties setting up the problem correctly. Now, I know that the drunk driver's care will have KE but the parked car will not. I know that the Wnc = Fd which means that it will be the displacement of the vehicles (39.5 m) times the Force (0.37) of the sliding friction on the road. What I am a bit confused on is how does potential energy (U) play into this equation. Any assistance or suggestions will be greatly appreciated.