I 2.1. The position of a robot moving along a straight track in the x direction is given by the function x(t) = (0.002 m/s) t + (0.05 m/s) t + (0.4 m/s) t between the times t = 0 and t = 20 s. (a) Use a graphing calculator or software to graph this function. From looking at the graph, what is the position and velocity of the robot at time t = 20 s? (Be careful, how can you tell from the graph what the velocity is?) (b) What is the position of the robot at t= 0s? 10 s? 15 s? (c) What is the average velocity of the robot during the first 10 s? during the full 20 s? (d) What is the instantaneous velocity of the robot at the time t 10 s? A Han