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 is all around us. Like gravity, friction is a force. More often than not, when people hear the word friction, they think about things rubbing together, and that's exactly what friction is! Whenever two things rub together, some of the energy they have is lost to friction. Basically, in things like car engines, the wheels of your skates, and the chain of your bike, friction is a force that slows you down.