1. The problem statement, all variables and given/known data A 70-kg, starting from rest, is pulled across a floor with a constant horizontal force of 200 N. For the first 10 m the floor is frictionless, and for the next 10 m the coefficient of friction is 0.30. What is the final speed of the crate? 2. Relevant equations W= -Delta PE Wnc= DELTA PE+DELTA KE F=ma Ff=MuFn W=Fd 3. The attempt at a solution What I tried is to calculate the total work. So I calculate the work being done frictionless. W=FD W=200(10) W=2000 Now I had to calculate work on friction W=FD W=(686)(.30)(10) W=2058 This is how far I have gotten.