What happens to velocity and temperature as a result of combustion?

• A. Increase velocity and temperature
• B. Decrease velocity and increase temperature
• C. Increase velocity and decrease temperature
• D. Decrease velocity and temperature

Answer: (A)

Combustion releases chemical energy as heat, so the products get hotter. That extra heat makes the gas expand and push outward faster, turning thermal energy into kinetic energy as the exhaust leaves the chamber. In propulsion, this high-temperature, high-velocity exhaust is what generates thrust, so both the temperature and the velocity increase. If temperature rose but velocity didn’t, or if temperature dropped, it wouldn’t reflect the reality of a combustion process in a propulsion context.