There are two broad classifications of frictional forces&colon; static friction and kinetic friction. These mechanical properties include the response of cartilage in frictional, compressive, shear and tensile loading. For more information on frictional forces, see friction. Thrust helps to keep the taper seated and provides essential frictional coupling. Viscous effects introduce frictional losses and time dependence. Viscosity is associated with the frictional forces in a flow. Due to frictional force, the velocity decreases in proportion to the acting frictional force. Newton also constructed a primitive form of a frictional electrostatic generator, using a glass globe. But even those are influenced by thermal and frictional forces. A very small amount of frictional energy would still be dissipated. Spin welding is a particular form of frictional welding. The water is created from ice that melts under high pressure from frictional heating. Plasticity can be accounted for by adding sliding frictional elements as shown in Figure 1. Structural unemployment is hard to separate empirically from frictional unemployment except that it lasts longer. Because the billet moves with the container the frictional forces are eliminated.