iÂ·deÂ·a. n. 1. Something, such as a thought or conception, that is the product of mental activity. 2. An opinion, conviction, or principle: has some strange political ideas. 3. A plan, purpose, or goal: She started school with the idea of becoming a doctor. 4.
The direction of the thrust is normally along the longitudinal axis of the rocket through the rocket center of gravity. But on some rockets, the exhaust nozzle and the thrust direction can be rotated, or gimbaled. The rocket can then be maneuvered by using the torque about the center of gravity. The magnitude of the thrust can be determined by the general thrust equation.
The re-action to the acceleration of the working fluid produces the thrust force on the engine. The working fluid is expelled from the engine in one direction and the thrust force is applied to the engine in the opposite direction. Forces are vector quantities having both a magnitude and a direction. When describing the action of forces, one must account for both the magnitude and the direction.