1. At time t=0s, an object is observed at x=0 m; and its position along the x axis follows this expression: x=4t+f, where the units for distance and time are meters and seconds, respectively. What is the object's displacement Ax between 1= 1.0s and 1=3.0 s? i) plug-in values, ii) write down results with units. A) +16 m B) -21 m C) +10 m D) +2 m E) -5 m Use the following to answer question 2: A racecar, traveling at constant speed, makes one lap around a circular track of radius r in a time t. Note: The circumference of a circle is given by C = 2r. 2. What is the average speed of the car for one complete lap? i) write down formula(s)/equation(s) {enclosed in boxes] ii) plug-in values A) B) 20 DB C) t 2r I 1 r 2xr D) I E) zero meters/second