History:
Draisienne
High Wheeler
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Perhaps the first bicycle ever built was created by a German inventor named Baron Karl von Drais de Sauerbrun in 1817. Baron von Sauerbrun created a wooden bicycle called a Draisienne. Like a modern bicycle, it had two wheels of equal size, and handlebars at the front. However, unlike a modern bicycle, a Draisienne had no pedals. Instead, a rider sat on the seat and walked the bicycle along the ground with their legs.
Pedals were first added to a bicycle in the 1860's, with the invention of the velocipede. Then, in 1870, James Starley created the "penny-farthing". The penny-farthing had a large front wheel and a small rear one (penny and farthing were two different sizes of British coins, and the name "penny-farthing" referred to the different size wheels). The penny-farthing and other bicycles of the type were referred to as "high wheelers" for their large front wheels. The downside of high wheeler bicycles was that they were unstable and difficult to ride. High-wheel bicycles remained popular up until 1876, when the "safety-bicycle" was invented. A safety bicycle, like a modern bicycle, had two equally sized wheels, which made it much less likely to unbalance or crash. Additionally, a safety bicycle was much easier to ride then a high wheeler. With the invention of safety bicycles, the popularity of the bicycle rose dramatically. Today, cycling remains a popular leisure pursuit, and many people use bicycles as a means of transportation, either for convenience or to reduce their carbon footprint. |
Mass and Balance:
Bicycles, as well as motorcycles and unicycles, are what is known as "single-track vehicles". A bicycle's wheels are along one line, as opposed to the side by side wheels of a car. Unlike four wheeled vehicles, single track vehicles cannot support themselves while stopped. When you stop on a bicycle, you need to put your foot down to keep your balance. However, when you pedal, both your feet are off the ground, yet, you remain balanced. A bicycle isn't stable when it's stopped, but it is stable when it moves.
A bicycle owes its stability to the concept of "center of mass". Center of mass, or center of gravity, is the point at an object at which the average mass of all the parts of the object, weighted with their distance from the point, is zero. This means that, if you hold an object at its center of mass, it will balance, because the mass of all the parts of the object not in contact with your hand will average to zero, canceling each other out. Thus, the object will have no tendency to tip or fall of your hand.
A bicycle remains stable so long as the center of mass remains centered above the wheels. When you ride a bicycle, you keep the center of mass over the wheels by steering and leaning. When moving in a straight line, remaining upright, and steering to counteract any wobbles, maintains stability. When turning, leaning is required to maintain stability, by balancing the outward pull of centripetal force.
Thus, a rider keeps a bicycle stable by keeping the center of mass over the wheels. However, scientists have discovered that, if released at the correct speed, a rider-less bicycle can self stabilize. Some believe this is because the wheels of a bicycle act as a gyroscope. A gyroscope is a device for maintaining orientation, usually utilizing a spinning wheel. Others believe that trail, the distance from where the steering axis intersects the ground to where the front wheel touches the ground, allows a bicycle to enter a stabilizing turn even with no rider to steer it. Thus a bicycle is able to balance itself, even rider-less.
How do bicycles relate to Newton's laws of motion? How do Newton's laws affect the behavior of bicycles? Newton's laws describe motion in terms of mass and force, and can be used to describe force, mass, and acceleration.
A bicycle owes its stability to the concept of "center of mass". Center of mass, or center of gravity, is the point at an object at which the average mass of all the parts of the object, weighted with their distance from the point, is zero. This means that, if you hold an object at its center of mass, it will balance, because the mass of all the parts of the object not in contact with your hand will average to zero, canceling each other out. Thus, the object will have no tendency to tip or fall of your hand.
A bicycle remains stable so long as the center of mass remains centered above the wheels. When you ride a bicycle, you keep the center of mass over the wheels by steering and leaning. When moving in a straight line, remaining upright, and steering to counteract any wobbles, maintains stability. When turning, leaning is required to maintain stability, by balancing the outward pull of centripetal force.
Thus, a rider keeps a bicycle stable by keeping the center of mass over the wheels. However, scientists have discovered that, if released at the correct speed, a rider-less bicycle can self stabilize. Some believe this is because the wheels of a bicycle act as a gyroscope. A gyroscope is a device for maintaining orientation, usually utilizing a spinning wheel. Others believe that trail, the distance from where the steering axis intersects the ground to where the front wheel touches the ground, allows a bicycle to enter a stabilizing turn even with no rider to steer it. Thus a bicycle is able to balance itself, even rider-less.
How do bicycles relate to Newton's laws of motion? How do Newton's laws affect the behavior of bicycles? Newton's laws describe motion in terms of mass and force, and can be used to describe force, mass, and acceleration.