A particle moves along the x axis. Its position is given by the equation x = 2.1 + 2.9t - 3.8t2 with x in meters and t in seconds. (a) Determine its position when it changes direction. m (b) Determine its velocity when it returns to the position it had at t = 0? (Indicate the direction of the velocity with the sign of your answer.) m/s

A particle moves along the x axis. Its position is given by the equation x = 2.1 + 2.9t - 3.8t2 with x in meters and t in seconds. (a) Determine its position when it changes direction. m (b) Determine its velocity when it returns to the position it had at t = 0? (Indicate the direction of the velocity with the sign of your answer.) m/s