In this way, heat inside Earth moves toward the cooler crust. This movement of rock is a COnvection Current<span>. </span>Convection Currents<span> in the mantle cause the movement of tectonic plates. Figure 4 </span>Convection currents in the atmosphere<span> form when cold </span>air<span>sinks and forces warm </span>air<span> away from Earth's surface.</span>
The attraction between two objects is force.
As such, if you don't describe the degree of attraction
in units of force, you're doomed.
Whether to use micronewtons, millinewtons, newtons,
giganewtons, ounces, pounds, or tons, really depends on
the size of the force, which in turn depends on the masses
of the two objects and the distance between them. You'll
want to select the unit that produces the most convenient
number. And of course, you'll want to favor the SI units.