A particle leaves the origin with an initial velocity v = (6.00 i) m/s and a constant acceleration a = (-1.00 i - 0.700 j) m/52 (a) What is the velocity of the particle when it reaches its maximum x coordinate? m/sit m/s j m/s k (b) What is the position vector of the particle at this time? mi+ mit m kA train moving at a constant speed of 54.0 km/h moves east for 39.0 min, then in a direction 60.0 east of due north for 10.0 min, and then west for 80.0 min. What is the average velocity of the train during this run? Magnitude km/h Direction . (counterclockwise from east)