A test driver at Incredible Motors, Inc., is testing a new model car having a speedometer calibrated to m/s read rather than mi/h The following series of speedometer readings was obtained during a test run: (a) Compute the average acceleration during each 2 s interval. (b) Make a velocity–time graph of the data shown, using scales of 1 cm = 1 s horizontally and 1 cm = 2 m/s vertically. Draw a smooth curve through the plotted points. By measuring the slope of your curve, find the magnitude of the instantaneous acceleration at times t=9 s, 13 s, and 15 s.