Torque Torque Torque, moment, or moment of force is the rotational equivalent of linear force. The concept originated with the studies of Archimedes on the usage of levers. Just as a linear force is a push or a pull, a torque can be thought of as a twist to an object. The symbol for torque is typically formula_1, the lowercase Greek letter "tau". When being referred to as moment of force, it is commonly denoted by "M". In three dimensions, the torque is a pseudovector; for point particles, it is given by the cross product of the position vector (distance vector)
Commonly used gamma-emitting isotopes Commonly used gamma-emitting isotopes Radionuclides which emit gamma radiation are valuable in a range of different industrial, scientific and medical technologies. This article lists some common gamma-emitting radionuclides of technological importance, and their properties. Many artificial radionuclides of technological importance are produced as fission products within nuclear reactors. A fission product is a nucleus with approximately half the mass of a uranium or plutonium nucleus which is left over after such a nucleus has been "split" in a nuclear fission reaction. Caesium-137 is one such radionuclide. It has a half-life of 30 years, and decays by pure beta decay to