The position of a car as a function of time t, with t > 0 and expressed in seconds, is (t) = [(66t 120) + (1.2 + 31.7t 8.71) ] ft. Determine the slope of the trajectory of the car for t = 1s and t = 3 s. In addition, find the angle between velocity and acceleration for t = 1 s and t = 3 s. Based on the values of at t and 12, argue whether the speed of the car is increasing or decreasing at t and 12. y x O Figure P12.13 and P12.14