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''.
Coefficient of friction. A coefficient of friction is a value that shows the relationship between the force of friction between two objects and the normal force between the objects. It is a value that is sometimes used in physics to find an object's normal force or frictional force when other methods aren't available.