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 force is the force arises between two surfaces in contact and is always in a direction opposite to the push. Force that acts on the object and brings it in motion is called unbalanced force. Unbalanced force causes change in speed of the object or change in the direction of the object.