LEEVENSPARK

| Background: A boomerang is an aerodynamically shaped object designed to fly efficiently through the air when thrown by hand. The term usually refers to an object made to follow a circular flight path that returns it to the thrower. (Some sources describe all aerodynamic "throwing sticks" as boomerangs, separating them into "returning" and "nonreturning" categories.) Traditional designs are V-shaped, but newer versions may have irregular shapes or more than two arms. Two design components give the boomerang the capability of circular flight. One is the arrangement of the arms, and the other is the airfoil profile shape that allows the arms into wings. During flight, the boomerang spins rapidly (about 10 revolutions per second). The wing profiles create the same lift effect that makes airplanes fly. In addition, the spinning motion creates gyroscopic precession, which pulls the boomerang into a circular path. A similar effect can be seen with a

Well,many of will be thinking that HOW AEROPLANES FLY??,Same question strike in my mind,so here is the answer for you guys. Drop a stone into the ocean and it will sink into the deep. Chuck a stone off the side of a mountain and it will plummet as well. Sure, steel ships can float and even very heavy airplanes can fly, but to achieve flight, you have to exploit the four basic aerodynamic fo rces: lift, weight, thrust and drag. You can think of them as four arms holding the plane in the air, each pushing from a different direction. First, let's examine thrust and drag. Thrust, whether caused by a propeller or a jet engine, is the aerodynamic force that pushes or pulls the airplane forward through space. The opposing aerodynamic force is drag, or the friction that resists the motion of an object moving through a fluid (or immobile in a moving fluid, as occurs when you fly a kite).If you stick your hand out of a car window while moving, you'll experience a very simple demon