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.
Thrust is the forward movement of the airplane, provided by the propellers or jet engines. Drag is the opposing force of the displaced air, the same force you feel walking into a strong wind. Gravity acts on the airplane, giving it weight. Lift counteracts the weight of the plane, keeping the airplane up in the air. The lift force is equal to the weight when an airplane is in level flight. Bernoulli's principle helps to explain lift. Bernoulli demonstrated that the faster a fluid moves, the less pressure it exerts.