10. A ball is thrown at an angle of 38° to the horizontal. What happens to the magnitude of the ball's vertical velocity during the time interval that the ball is in the air?
9. A baseball is thrown at an angle of 40.09° above the horizontal. The horizontal component of the baseball's initial velocity is 12.0 meters per second. What is the magnitude of the ball's initial velocity?
12. For two vectors to give a maximum resultant, the angle between them should be 90°.