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''.
1 Dry friction is directly proportional to the normal force between the two surfaces in contact. 2  Dry friction depends on the materials in contact. This factor is measured by the quantity known as the coefficient of friction which isâ¦.  the ratio of the friction force to the normal force.