The graph below depicts the velocity of a coasting cart vs. clock time. Construct a good straight-line model for this data and use your model to determine the velocity of the cart at clock time t = 55 sec. Determine also the clock time at which velocity will be 42 cm/sec . The x axis is marked in units of 15 sec and the y axis in units of 25 cm/s, both starting at (0,0).