Conservation of linear momentum applies when the net external force is negligible, even in the presence of gravity. The discussion highlights that during short time spans, such as an explosion, the effects of gravity and other forces become minimal, allowing momentum to be considered conserved. It emphasizes that real-life physics often involves approximations, including neglecting air drag and variations in gravitational force. The argument suggests that while gravity exists, its impact on momentum conservation can be considered small in specific scenarios. Overall, the solution presented is deemed correct under the discussed conditions.
