In the scaled diagram, two forces, F1 and F2 , act on a 4.0-kilogram block at point P. Force F1 has a magnitude of 12 Newtons, and is directed toward the right. Force F2 has a magnitude of 5 Newtons and is directed toward the left.

The earth's magnetic field, with a magnetic dipole moment of 8.0×1022am2, is generated by currents within the molten iron of the earth's outer core. suppose we model the core current as a 3000-km-diameter current loop made from a 1000-km-diameter “wire.” the loop diameter is measured from the centers of this very fat wire.to decide whether this is a large or a small current density, compare it to the current density of a 7.0 a current in a 2.0-mm-diameter wire.