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.
As the temperature of the air increases its density decreases. Therefore the thrust produced by the engine decreases. As the air pressure increases, its density increases, causing thrust produced by the engine to increase. Altitude has a double effect on thrust. As the altitude increases, the air becomes colder and denser, up to the beginning of stratosphere. This causes the thrust to increase.