A moderate wind accelerates a pebble over a horizontal xy plane with a constant acceleration a = (5.01 + 7.0) m/s. At time t = 0, the velocity is (5.0) m/s. What are the (a) magnitude and (b) angle of its velocity when it has been displaced by 11.0 m parallel to the x axis? (a) Number Units m/s (b) Number i Units