"A racquetball of mass m = 43.3 g, initially moving at 40.0 m/s horizontally in the positive x direction, is struck by a racket. After being struck, the ball moves back in the opposite direction at an angle of 20.0° above the horizontal with a speed of 57.0 m/s. What is the average vector force exerted on the racket by the ball if they are in contact for 2.40 ms? (Assume the positive y direction is vertically upward. Express your answer in vector form.)"