1. The problem statement, all variables and given/known data The graph shows the speed as a function of time for a minivan, coasting on neutral along a straight, level road, loaded with windsurfing equipment and towing a boat.The total mass is 2450kg (weight = 5402lbs). Find the size of the force due to wind and rolling friction when the van speed is 49.27mph (1mph= 0.447m/s). 2. Relevant equations delta v/delta t=a F=ma 3. The attempt at a solution I converted the mph to m/s, and I drew a line tangent to the point on the graph where the speed is 49.27 mph. I just can't seem to get the numbers right for some reason. Can someone help me out?