Which fluid force opposes lift

Answer 1

Answer The essence of your question is very complicated and concerns fluid mechanics but I will simplify it as much as possible. In short, the force that opposes lift is weight (the gravitational force acting on an object's mass). If lift is greater than weight leaving all other variables such as air resistance are left the same the object is ascend. If weight is greater than lift the object will descend if already in the air or never take off if still on the ground. This question is at the heart of why planes fly. The leading edge of the wing causes the air on top to travel than the air on the bottom. Bernoulli's principle says as the speed of a fluid increases the pressure of the fluid decreases. As a result, the air on top of the wing has a lower pressure than the air on the bottom. Fluid go from high to low pressure. The air on the bottom of the wing exerts a force upward and thus the plane rises. It is important to know the other two force crucial in the flying of plane. They are thrust and drag. Thrust is the reactionary force to the force that push air out of a jet engine or from propellers. Drag is the force of air resistance and it is proportional to the velocity of the object. In other words, as the object goes faster the force trying to slow it down increases as well. This continues until the object reaches terminal velocity. Terminal velocity is the point at which the force acting on an object and the frictional force become equal in magnitude and opposite in direction. As a result, the net force acting on the object is zero and the object stops accelerating and falls at a constant rate from that point on.

Answer 2

Drag