How is a comet propelled from a mortar tube?

A comet is propelled from a mortar tube using a charge of black powder. When the fuse ignites the black powder, it generates a rapid expansion of gases that create a high-pressure environment within the tube. This pressure forces the comet out of the mortar tube at a high velocity. The combustion of black powder is essential because it provides the necessary energy to overcome gravity and any friction that might impede the comet's motion.

The combustion process is critical in ensuring the comet is accelerated properly to achieve the desired height and effect in the sky during a fireworks display. Other methods, such as an electric spark or mechanical lever, are not used in this context, as they do not provide the necessary propulsion or explosive energy required for the effective launch of fireworks. Gravitational force alone is insufficient to propel a comet from a mortar tube, as more significant force is needed to achieve the launch velocity.