A torsion spring or torsion catapult is an elastic material that reacts against torsion (twisting motion). In particular, the more one twists it, the more force it takes to twist it further. A torsion spring is often made from a wire, ribbon, bar, or coil. Helical or coil springs designed for tension A spring is a flexible elastic object used to store mechanical energy. ... Look up torsion in Wiktionary, the free dictionary. ...

Torsion circles are used in torsion catapult clocks, where a weight is spun, oscillating in its spinning direction at the bottom of the clock. As the resonant period is very long, this mechanism is used in spring wound clocks designed to operate for an entire month or even a year without rewinding. This type of suspension is also used in sensitive devices used to determine constants associated with the gravitational effects of mass. Gravity is a force of attraction that acts between bodies that have mass. ... Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ...

Torsion bars (or sway bars) are used to support automobile suspension components, allowing those components (which indirectly support the wheels) to move in response to rough roads while allowing a smooth ride in the vehicle. The DeLorean DMC-12 uses cryogenically tempered torsion bars to assist with the opening of its gull wing doors. See torsion beam suspension. Since sway bars 'tie' the left and right suspension together, some offroad enthusiasts install quick disconnect sway bar links to allow the sway bar to be disconnected for greater articulation when offroading. Karl Benzs Velo (vélo means bicycle in French) model (1894) - entered into the first automobile race 2005 MINI Cooper S. An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. ... The front suspension components of a Ford Model T. Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. ... The De Lorean DMC-12 is an Irish sports car which was manufactured by the De Lorean Motor Company from 1981 through 1983. ... Cryogenics is the study of very low temperatures or the production of the same, and is often confused with cryobiology, the study of the effect of low temperatures on organisms, or the study of cryopreservation. ... A De Lorean DMC-12 with its doors open A Bricklin SV-1 with its doors open A Mercedes-Benz 300SL Gullwing with its doors open The term gull-wing door is used to describe automobile doors which are hinged at the roof. ... Torsion beam suspension, also known as a torsion bar or torsion spring suspension, is a vehicle suspension system. ...

Coiled torsion springs are coils that are twisted (rather than pulled) to store energy.

Large coiled torsion springs are used to counter-balance the weight of garage doors. Great care must be exercised when adjusting these as they store a large amount of mechanical energy. This page is a candidate to be copied to Wiktionary. ... In physics, mechanical energy describes the potential energy and kinetic energy present in the components of a mechanical system. ...

Small coiled torsion springs are often used to operate small pop-up doors such as are found on small consumer goods such as digital cameras and compact disk players. Small but strong coiled torsion springs are used in the construction of traditional springloaded-bar type mousetraps. This article or section does not adequately cite its references or sources. ... CD redirects here; see Cd for other meanings of CD. Image of a compact disc (pencil included for scale) A compact disc (or CD) is an optical disc used to store digital data, originally developed for storing digital audio. ... This article or section does not cite its references or sources. ...

Oscillatory motion of torsion pendulums

Torsion pendulums undergo oscillatory motion similar to springs. It oscillates (twists and untwists) after being given an initial torque. Helical or coil springs designed for tension A spring is a flexible elastic object used to store mechanical energy. ... It has been suggested that this article or section be merged with Moment (physics). ...

If I is the moment of inertia of a body with respect to its axis of oscillation, and if K is the torsion coefficient of the fiber (torque required to twist it through an angle of one radian), then the period of oscillation of a torsion pendulum is given by Moment of inertia, also called mass moment of inertia and, sometimes, the angular mass, (SI units kg m², Former British units slug ft2) quantifies the rotational inertia of a rigid body, i. ... A torsion coefficient is used to describe torsional springs. ... It has been suggested that this article or section be merged with Moment (physics). ... Some common angles, measured in radians. ...

Both I and K may have to be determined by experiment. This can be done by measuring the period T and then adding to the suspended body another body of known moment of inertia I', giving a new period of oscillation T'

and then solving the two equations to get

The oscillating balance wheel of a watch is in effect a torsion pendulum, with the suspending fiber replaced by hairspring and pivots. The watch is regulated, first roughly by adjusting I (the purpose of the screws set radially into the rim of the wheel) and then more accurately by changing the free length of the hairspring and hence the torsion coefficient K.

Damped pendulum

The pendulum equation does not take into account the effects of friction and dissipation. While these effects can be very complicated to model, a good approximation is to add a term proportional to the velocity:

The positive constant γ is the viscous damping parameter. A system described by this equation is called a damped pendulum.

The Torsion Balance

The torsion balance is a device created by Charles-Augustin de Coulomb in 1777, to measure very weak forces. Coulomb used it to measure the electrostatic force between two charges. He found that the electrostatic force between two point charges is directly proportional to the magnitudes of each charge and inversely proportional to the square of the distance between the charges. This finding is called Coulomb's law. Portrait of Coulomb Charles Augustin Coulomb (June 14, 1736 – August 23, 1806) was a French physicist. ... In physics, the electrostatic force is the force arising between static (that is, non-moving) electric charges. ... Coulombs torsion balance In physics, Coulombs law is an inverse-square law indicating the magnitude and direction of electrostatic force that one stationary, electrically charged object of small dimensions (ideally, a point source) exerts on another. ...

The torsion balance consists of two metal balls attached to the ends of an insulating rod suspended from the middle by a thin fiber. To measure the electrostatic force we charge one of the two balls, and then place near it a third ball with a similar charge. The two charged balls repel each other, causing the fiber to twist to a certain angle. If we then measure how much force, in newtons, is required to twist the fiber to that same angle, we then know how much force was exerted upon the fiber by the two balls and therefore the force between the balls. The newton (symbol: N) is the SI unit of force. ...

The unit Charles Augustine de Coulomb used to measure this electrostatic force was named after him: the coulomb. One coulomb is the amount of charge accumulated in one second by a current of one ampere. Therefore a coulomb is one ampere flowing multiplied by one second, and the formula for that is: 1 C = 1 A·s. One coulomb represents a charge of approximately 6.241506 x 10¹⁸ e, e being the amount of electric charge on one electron. The coulomb (symbol: C) is the SI unit of electric charge. ... Current can be measured by a galvanometer, via the deflection of a magnetic needle in the magnetic field created by the current. ...

There are, at first glance, a few setbacks to this device, one of them being that you are finding the charge of two metal balls when you might actually want to find the charge of two pieces of wool, or two pieces of plastic. The solution to that, however, is simple: you simply replace the metal balls with equally sized spherical samples of the item you’d like to measure.

Another difficulty is that both charged balls must have the exact same amount of charge on them. Coulomb solved this by discovering that two objects of the same size and shape charged to the same potential will have the same charge; so if the two balls are touched together, they will divide the charge equally.

A torsion balance was used in the Cavendish experiment in 1798 to measure the denisty of the Earth (not the gravitational constant as is commonly claimed). Torsion balances are still used in physics experiments. In physics, the Cavendish experiment was the first experiment to accurately measure the gravitational constant by measuring the force of gravity between two masses in the laboratory. ... According to the law of universal gravitation, the attractive force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. ...

Media

• Media on Torsion spring in the Wikicommons.

The torsion balance is a device created by Charles-Augustin de Coulomb in 1777, to measure very weak forces. Coulomb used it to measure the electrostatic force between two charges. He found that the electrostatic force between two point charges is directly proportional to the magnitudes of each charge and inversely proportional to the square of the distance between the charges. This finding is called Coulomb's law. Image File history File links Torsion-pendulum. ... A kilobyte (derived from the SI prefix kilo-, meaning 1000) is a unit of information or computer storage equal to the decimal 1024 bytes (2 to the 10th power, or 1,024 bytes based in the binary system). ... Look up Ogg in Wiktionary, the free dictionary. ... Theora is a video codec being developed by the Xiph. ... Image File history File links Commons-logo. ... The Wikimedia Commons (also called Commons or Wikicommons) is a repository of free images, sound and other multimedia files. ...

The torsion balance consists of two metal balls attached to the ends of an insulating rod suspended from the middle by a thin fiber. To measure the electrostatic force we charge one of the two balls, and then place near it a third ball with a similar charge. The two charged balls repel each other, causing the fiber to twist to a certain angle. If we then measure how much force, in newtons, is required to twist the fiber to that same angle, we then know how much force was exerted upon the fiber by the two balls and therefore the force between the balls.

The unit Charles Augustine de Coulomb used to measure this electrostatic force was named after him: the coulomb. One coulomb is the amount of charge accumulated in one second by a current of one ampere. Therefore a coulomb is one ampere flowing multiplied by one second, and the formula for that is: 1 C = 1 A·s. One coulomb represents a charge of approximately 6.241506 x 1018 e, e being the amount of electric charge on one electron.

There are, at first glance, a few setbacks to this device, one of them being that you are finding the charge of two metal balls when you might actually want to find the charge of two pieces of wool, or two pieces of plastic. The solution to that, however, is simple: you simply replace the metal balls with equally sized spherical samples of the item you’d like to measure.

Another difficulty is that both charged balls must have the exact same amount of charge on them. Coulomb solved this by discovering that two objects of the same size and shape charged to the same potential will have the same charge; so if the two balls are touched together, they will divide the charge equally.

A torsion balance was used in the Cavendish experiment in 1797 to measure the density of the Earth (not the gravitational constant as is commonly claimed). Torsion balances are still used in physics experiments.

See also

• Slinky

Metal Slinky Rainbow-colored plastic Slinky A Slinky, or Lazy-Spring, is a coil-shaped toy, invented by mechanical engineer Richard James in Philadelphia, Pennsylvania. ...

External links

• Garage Door Torsion Spring Replacement tutorial by Richard J Kinch. Includes analysis and engineering formulas to compute general torsion spring properties.
• How To Replace Garage Door Torsion Springs by Dan Musick
• Measuring Big G, J.H. Gundlach, Measurement Sci.& Tech. 10 454 (1999) (Recent physics experiment at the University of Washington using a torsion balance)

Rice,Jerry September 19,2003 "Earth's Magnetic Pulses"