A marksman fires a practice round from A toward a target B. If the target diameter is 180 mm and the target center is at the same altitude as the end of the rifle barrel, determine the range of "shallow" launch angles for which the round will strike the target. Neglect aerodynamic drag and assume that the round is directed along the vertical centerline of the target. (Note: The word "shallow" indicates a low-flying trajectory for the round.)

A marksman fires a practice round from A toward a target B. If the target diameter is 180 mm and the target center is at the same altitude as the end of the rifle barrel, determine the range of "shallow" launch angles for which the round will strike the target. Neglect aerodynamic drag and assume that the round is directed along the vertical centerline of the target. (Note: The word "shallow" indicates a low-flying trajectory for the round.)