What happens to ocean water as it moves from antarctica to the equator?

it transfers thermal energy to deeper layers of the ocean.

it becomes less dense and rises to the surface.

it transfers thermal energy to the area, warming the equatorial waters.

it becomes more dense and sinks to the ocean bottom

Asquare isothermal chip is of width w=5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated; the front surface is exposed to the flow of a coolant at tinf=15 °c. from reliability considerations, the chip temperature must not exceed t=85 °c. if the coolant is air and the corresponding convection coefficient is h=200 w/m2 x k, what is the maximum allowable "power" of the chip? if the coolant is a liquid for which h=3000 w/m2 x k, what is the maximum allowable power of the chip?