The metric or SI (Le SystÃ¨me International d'UnitÃ©s) system of units has many derived units from the seven base units. A derived unit would be a unit that is a combination of base units. Density would be an example where density = mass/volume or kg/m3. Many derived units have special names for the properties or measurements they represent. This table lists eighteen of these specialized units along with their basic unit factors.
Cadence (cycling) In cycling, cadence (or pedalling rate) is the number of revolutions of the crank per minute; this is the rate at which a cyclist is pedalling/turning the pedals. Cadence is directly proportional to wheel speed, but is a distinct measurement and changes with gearingâwhich determines the ratio of crank rpm to wheel rpm.
Classic bell of a bicycle. A bicycle, also called a cycle or bike, is a human-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist, or bicyclist. Bicycles were introduced in the late 19th century in Europe, and by the early 21st century, more than 1 billion have been produced worldwide. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of tra