1. The problem statement, all variables and given/known data A toy car of mass 20kg moves down a slope of length 35m, which is inclined at arcsin(2/7) to the horizontal. The height of the car initially is 10m, and a constant frictional force of 100N acts against the car through motion. Calculate the work done, power and efficiency of the system: 3. The attempt at a solution My initial issue here is calculating the work done by the car travelling down the entirety of the slope. I'm not sure whether the work done is just the friction force x distance which would give 3500J, or whether you need to take into account the horizontal component of the cars weight when descending the slope, resolving horizontally? Any advice here would be greatly appreciated! Thanks.