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Buzzer (whirligig)
A whirligig is an object that spins or whirls, or has at least one part that spins or whirls. It can also be a Pinwheel (toy), pinwheel, Top (toy), spinning top, buzzer, comic weathervane, gee-haw, spinner, whirlygig, whirlijig, whirlyjig, whirlybird, or simply a whirly. They are most commonly powered by the wind but can be hand-, friction- or motor-powered. They can be used as kinetic art, kinetic garden ornaments, and can be designed to transmit sound and vibration into the ground to repel burrowing rodents. Types Whirligigs can be divided into four categories: button, friction, twine, string, and wind-driven. Button whirligigs Button whirligigs, also known as button spinners and Buzzer (whirligig), buzzers, are the oldest known whirligigs. They require only a piece of clay or bone and a strip of hide. The ancient Greeks had their own version of this toy, called an ''iynx'', and Indigenous peoples of the Americas, Native American cultures had another in 500 BC. Many a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourche Maline (Oklahoma Stream)
Fourche Maline (pronounced foosh-ma-lean) (''Bad Fork'', French) is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed June 3, 2011 tributary of the Poteau River in Oklahoma. The headwaters of Fourche Maline are in the Sans Bois Mountains in northwest Latimer County. It flows southwestward through Robbers Cave State Park, then southeastward past Wilburton before turning eastward until it reaches the Poteau River in Le Flore County. Fourche Maline's confluence with the Poteau River is now submerged in Lake Wister, about south of the confluence. The distance from origin to confluence is about ''Wister Lake O & M Program, Poteau River: Environmental Impact Statement''. June ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Speed
Terminal velocity is the maximum speed attainable by an object as it falls through a fluid (air is the most common example). It is reached when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of gravity (''FG'') acting on the object. Since the net force on the object is zero, the object has zero acceleration. For objects falling through air at normal pressure, the buoyant force is usually dismissed and not taken into account, as its effects are negligible. As the speed of an object increases, so does the drag force acting on it, which also depends on the substance it is passing through (for example air or water). At some speed, the drag or force of resistance will be equal to the gravitational pull on the object. At this point the object stops accelerating and continues falling at a constant speed called the terminal velocity (also called settling velocity). An object moving downward faster than the terminal velocity (for example because it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotational Energy
Rotational energy or angular kinetic energy is kinetic energy due to the rotation of an object and is part of its total kinetic energy. Looking at rotational energy separately around an object's axis of rotation, the following dependence on the object's moment of inertia is observed: E_\text = \tfrac I \omega^2 where The mechanical work required for or applied during rotation is the torque times the rotation angle. The instantaneous power of an angularly accelerating body is the torque times the angular velocity. For free-floating (unattached) objects, the axis of rotation is commonly around its center of mass. Note the close relationship between the result for rotational energy and the energy held by linear (or translational) motion: E_\text = \tfrac m v^2 In the rotating system, the moment of inertia, ''I'', takes the role of the mass, ''m'', and the angular velocity, \omega , takes the role of the linear velocity, ''v''. The rotational energy of a rolling cylinder varie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardinal Whirligig
Cardinal or The Cardinal most commonly refers to * Cardinalidae, a family of North and South American birds **''Cardinalis'', genus of three species in the family Cardinalidae ***Northern cardinal, ''Cardinalis cardinalis'', the common cardinal of eastern North America ***Pyrrhuloxia or desert cardinal, ''Cardinalis sinuatus'', found in southwest North America ***Vermilion cardinal, ''Cardinalis phoeniceus'', found in Colombia and Venezuela * Cardinal (Catholic Church), a senior official of the Catholic Church **Member of the College of Cardinals * Cardinal Health, a health care services company * Cardinal number ** Large cardinal * Cardinal direction, one of the four primary directions: north, south, east, and west * Arizona Cardinals, an American professional football team * St. Louis Cardinals, an American professional baseball team Cardinal or The Cardinal may also refer to: Animals Birds In addition to the aforementioned cardinalids: * ''Paroaria'', a South American genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gee-haw Whammy Diddle
A gee-haw whammy diddle is a Mechanical system, mechanical toy consisting of two wooden sticks. One has a series of notches cut transversely along its side and a smaller wooden stick or a propeller attached to the end with a nail or pin. This stick is held stationary in one hand with the notches up, and the other stick is rubbed rapidly back and forth across the notches. This causes the propeller to rotate. Sometimes also known as a ouija windmill, a hoodoo stick or a VooDoo stick. The word ''whammy'' is sometimes ''whimmy,'' and the word ''diddle'' sometimes ''doodle'', giving it three possible other names, and the ''gee-haw'' may also be dropped. ''Gee-haw'' refers to the fact that, by rubbing a finger against the notched stick while rubbing, the direction of the spinning propeller may be reversed. The operator may do this surreptitiously and yell "gee" or "haw" to make it appear that the propeller is reacting to the commands. When called a ''hooey stick'', the word "hooey" is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller (aircraft)
In aeronautics, an aircraft propeller, also called an airscrew,Beaumont, R.A.; ''Aeronautical Engineering'', Odhams, 1942, Chapter 13, "Airscrews". converts rotary motion from an engine or other power source into a swirling slipstream which pushes the propeller forwards or backwards. It comprises a rotating power-driven hub, to which are attached several radial airfoil-section blades such that the whole assembly rotates about a longitudinal axis. The blade pitch may be fixed, manually variable to a few set positions, or of the automatically variable "constant-speed" type. The propeller attaches to the power source's driveshaft either directly or through reduction gearing. Propellers can be made from wood, metal or composite materials. Propellers are most suitable for use at subsonic airspeeds generally below about , although supersonic speeds were achieved in the McDonnell XF-88B experimental propeller-equipped aircraft. Supersonic tip-speeds are used in some aircraft like the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamboo-copter
The bamboo-copter, also known as the bamboo dragonfly or Chinese top ( Chinese ''zhuqingting'' (竹蜻蜓), Japanese ''taketonbo'' ), is a toy helicopter rotor that flies up when its shaft is rapidly spun. This helicopter-like top originated in Jin dynasty China around 320 AD, and was the object of early experiments by English engineer George Cayley, the inventor of modern aeronautics.Leishman, J. Gordon (2006)''Principles of Helicopter Aerodynamics'' Cambridge University Press. pp. 7–9. In China, the earliest known flying toys consisted of feathers at the end of a stick, which was rapidly spun between the hands and released into flight. "While the Chinese top was no more than a toy, it is perhaps the first tangible device of what we may understand as a helicopter." The Jin dynasty Daoist philosopher Ge Hong's (c. 317) book '' Baopuzi'' (抱樸子 "Master Who Embraces Simplicity") mentioned a flying vehicle in what Joseph Needham calls "truly an astonishing passage".J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
