What is the purpose of a domain?

A principle of material science which expect that bunches of particles delivered by development of electrons adjust themselves in bunches (called "spaces") in attractive materials. The heading of attractive field at a point is the heading to which a free north shaft would move in the event that set at that point within the field.

the tires are rotating at 0.434 rpmlinear speed=45 m/sdiameter=0.550 mradius=0.275 mnow v= rωω= v/rω=45/0.275ω=163.6 rad/sω=163.6 rad/s (1rev/2π rad) (60s/1m)ω=1563 rpm