1. The problem statement, all variables and given/known data A 2100 kg car accelerates from rest at the top of a driveway that is sloped at an angle of 20.0º with the horizontal. An average friction force of 4000 impedes the car's motion so that the car's speed at the bottom of the driveway is 3.8 m/s. What is the length of the driveway? 2. Relevant equations Wnet=Change in Kinetic Energy KE=.5mv^2 Work=FDcos(theta) 3. The attempt at a solution FDcos(theta)=.5mv^2(final)-.5mv^2(initial) 4000(2100)(9.8)dcos(20)=.5(2100)(3.8)^2 d= ((3.8)^2/(4000(9.8)cos(20))) d= Some tiny decimal. The book answer is 5.1m Where did i go wrong, and how can i fix it?