Agate is good protective energy stone, especially for children, and is very calming and soothing. It also can help strengthen the body's connection to the earth.
The friction factor, f, is a dimensionless factor that depends primarily on the velocity u, diameter D, density Ï, and viscosity Î·. It is also a function of wall roughness which depends on the size Îµ, spacing Îµ' and shape of the roughness elements characterized by Îµ''.
Friction. the mechanical resistance that arises in the plane of contact between two bodies during their relative movement. The force of resistance F, which is directed opposite to the relative movement of the given body, is called the frictional force acting on the body.