An ice skater starts out traveling with a velocity of (3.0, 7.0) m/s. He performs a 3.0 second maneuver and ends with a velocity of (0, 5.0) m/s. (a) What is his average acceleration over this period? (b) A different ice skater starts with the same initial velocity, accelerates at (1.5, 3.5) m/s2 for 2.0 seconds, and then at (0, 5.0) m/s2 for 1.0 seconds. What is his final velocity?