Identify the force that propels a rocket. The rocket is propelled by the reaction force from the particles accelerated out the rear by an action force from the rocket. The rocket is propelled because the action force of the rocket on the exhaust gases is less than than the reaction force of the exhaust gasses on the rocket. The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. The rocket is propelled because the action force of the rocket on the exhaust gases is greater than the reaction force of the exhaust gasses on the rocket.