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Bicycle And Motorcycle Dynamics
Bicycle and motorcycle dynamics is the science of the motion of bicycles and motorcycles and their components, due to the forces acting on them. Dynamics falls under a branch of physics known as classical mechanics. Bike motions of interest include balancing, steering, braking, accelerating, suspension activation, and vibration. The study of these motions began in the late 19th century and continues today. Bicycles and motorcycles are both single-track vehicles and so their motions have many fundamental attributes in common and are fundamentally different from and more difficult to study than other wheeled vehicles such as dicycles, tricycles, and quadracycles. As with unicycles, bikes lack lateral stability when stationary, and under most circumstances can only remain upright when moving forward. Experimentation and mathematical analysis Analysis is the branch of mathematics dealing with continuous functions, limit (mathematics), limits, and related theories, such as Der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed
In everyday use and in kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed is not the same as velocity. Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second (m/s), but the most common unit of speed in everyday usage is the kilometre per hour (km/h) or, in the US and the UK, miles per hour (mph). For air and marine travel, the knot is commonly used. The fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in a vacuum ''c'' = metres per second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle And Motorcycle Geometry
Bicycle and motorcycle geometry is the collection of key measurements (lengths and angles) that define a particular bike configuration. Primary among these are wheelbase, steering axis angle, fork offset, and trail. These parameters have a major influence on how a bike handles. Wheelbase Wheelbase is the ''horizontal'' distance between the centers (or the ground contact points) of the front and rear wheels. Wheelbase is a function of rear frame length, steering axis angle, and fork offset. It is similar to the term wheelbase used for automobiles and trains. Wheelbase has a major influence on the longitudinal stability of a bike, along with the height of the center of mass of the combined bike and rider. Short bikes are much more suitable for performing wheelies and stoppies. Steering axis angle The steering axis angle is called caster angle when measured from vertical axis or head angle when measured from horizontal axis. The steering axis is the axis about which the steeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroscopic
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. Gyroscopes based on other operating principles also exist, such as the microchip-packaged MEMS gyroscopes found in electronic devices (sometimes called gyrometers), solid-state ring lasers, fibre optic gyroscopes, and the extremely sensitive quantum gyroscope. Applications of gyroscopes include inertial navigation systems, such as in the Hubble Space Telescope, or inside the steel hull of a submerged submarine. Due to their precision, gyroscopes are also used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Center Of Mass
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may be applied to cause a linear acceleration without an angular acceleration. Calculations in mechanics are often simplified when formulated with respect to the center of mass. It is a hypothetical point where the entire mass of an object may be assumed to be concentrated to visualise its motion. In other words, the center of mass is the particle equivalent of a given object for application of Newton's laws of motion. In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe. In the case of a dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Model
A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used in the natural sciences (such as physics, biology, earth science, chemistry) and engineering disciplines (such as computer science, electrical engineering), as well as in non-physical systems such as the social sciences (such as economics, psychology, sociology, political science). The use of mathematical models to solve problems in business or military operations is a large part of the field of operations research. Mathematical models are also used in music, linguistics, and philosophy (for example, intensively in analytic philosophy). A model may help to explain a system and to study the effects of different components, and to make predictions about behavior. Elements of a mathematical model Mathematical models can take many forms, including dynamical systems, statisti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experiment
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into Causality, cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experiment, natural experimental studies. A child may carry out basic experiments to understand how things fall to the ground, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, especially when used over time. Experiments can vary from personal and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicycle
A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a bicycle frame, frame with a bicycle saddle, saddle, and has a human-powered vehicle, pedal-driven direct-drive mechanism, direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performance, street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or Mountain bike trials, trials. History US patents for single-wheeled 'velocipedes' were published in 1869 by Frederick Myers and in 1881 by Battista Scuri. Unicycle design has developed since the Penny Farthing and later the advent of the first unicycle into many variations including: the seatless unicycle ("ultimate wheel") and the tall ("giraffe") unicycle. During the late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAE International
SAE International, formerly named the Society of Automotive Engineers, is a United States-based, globally active professional association and standards developing organization for engineering professionals in various industries. SAE International's world headquarters is in Warrendale, Pennsylvania, 20 miles north of Pittsburgh, Pennsylvania. Principal emphasis is placed on global transport industries such as aerospace, automotive, and commercial vehicles. The organization adopted the name SAE International to reflect the broader emphasis on mobility. SAE International has over 138,000 global members. Membership is granted to individuals, rather than companies. Aside from its standardization efforts, SAE International also devotes resources to projects and programs in STEM education, professional certification, and collegiate design competitions. For historical legacy reasons, the label "SAE" is commonly used on tools and hardware in North America to indicate United States ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadracycle
A quadracycle is a four-wheeled human-powered land vehicle. It is also referred to as a quadricycle, quadcycle, pedal car or four-wheeled bicycle amongst other terms. Quadracycles have been in use since 1853 and have grown into several families of vehicles for a variety of purposes, including tourist rentals, pedal taxis, private touring, mountain and industrial use. Nomenclature There is no consensus amongst manufacturers of four-wheeled, human-powered vehicles as to what this class of vehicles should be called, although ''quadracycle'' is the most commonly used term. Manufacturers who do refer to their products by class of vehicle call them: *Quadracycle - 11 manufacturers *Four-wheel bicycle - 7 manufacturers *Quadricycle - 5 manufacturers *Quadcycle - 3 manufacturers *Pedal car - 2 manufacturers *Quad - 2 manufacturers In addition there are single manufacturers who call them Go-kart, Car, Car-Bike, Ecological car, Human Powered Vehicle, Pedal Kart, Quadribent, Quattrocy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricycle
A tricycle, sometimes abbreviated to trike, is a human-powered (or gasoline or electric motor powered or assisted, or gravity powered) three-wheeled vehicle. Some tricycles, such as cycle rickshaws (for passenger transport) and freight trikes, are used for commercial purposes, especially in the developing world, particularly Africa and Asia. In the West, adult-sized tricycles are used primarily for recreation, shopping, and exercise. Tricycles are favoured by children and senior adults for their apparent stability versus a bicycle; however a conventional trike has poor dynamic lateral stability, and the rider must take care when cornering to avoid tipping the trike over. Unconventional designs such as recumbents have a lower centre of gravity so require less care. History A three-wheeled wheelchair was built in 1655 or 1680 by a disabled German man, Stephan Farffler, who wanted to be able to maintain his mobility. A watch-maker, Farffler created a vehicle that was powered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
