F 07 (2 marks) An equation used by investigators at accident scenes was introduced in Lesson 1. To determine the vehicle's speed before the collision, investigators may use the formula S - 15.9 /Lf, where S is the speed in kilometres per hour of the vehicle, L is the length of the skid marks in metres, and f is the coefficient of friction. The skid mark was left by the rubber tires on wet asphalt. If the speed of the vehicle was 60 km/h and the length of the skid marks was 28 m, determine the coefficient f. a. state the function(s) you graphed (2 marks) b. State the coefficient f, correct to the nearest hundredth (1 mark)