Elasticity
Elastic force (elastic force) refers to the occurrence of elastic deformation of the object due to restore the status quo, the contact with his objects generated force. But if the deformation is too large, that is more than the elastic limit is no longer produce elastic. When the elastic force is generated, the object with the elastic deformation is the force object, and the object that it touches is the force object. Usually refers to the elasticity is generally pressure, support and tension. The deformation of the object, if restored to the original state, this deformation is called elastic deformation; the other hand, if a certain limit can not be restored to the original state, this deformation is called plastic deformation. This limit is called the elastic limit. Any object can be deformed, no deformation of the object is not present. But in scientific problems people will assume that no deformation of the object called rigid body, which is an ideal model. The reason why some people think that some objects do not occur because some deformation is obvious, such as the expansion and elongation of the spring, bamboo wind bending; and some are not so obvious, you need to use the instrument can be observed, such as the book On the table, the table and the book are subject to the role of the occurrence of deformation, but barely can not be observed with the naked eye. ...