Answer
abc. Negative x, speeding up, negative acceleration.
def. Positive x, speeding up, positive acceleration.
g. No change, speed is zero, acceleration is zero.
Work Step by Step
abc. During the interval from A to B, it is moving in the negative x-direction (its displacement is negative), speeding up (the magnitude of the slope of the x-t graph is increasing), and the acceleration is negative (the position-time graph is concave down).
def. During the interval from D to E, it is moving in the positive x-direction (its displacement is positive), speeding up (the magnitude of the slope of the x-t graph is increasing), and the acceleration is positive (the position-time graph is concave up).
g. During the interval from C to D, the object is not moving at all, remains stationary, and the acceleration is zero.
