Examine the temperature profile for the low latitudes (Fig. 1a).Most of the sunlight entering the ocean is absorbed very near the surface. This sun-warmed surface water mixes with cooler, deeper waters as winds, breaking waves, and turbulent currents stir the water. One result of this mixing is a surface layer having nearly uniform temperature, or isothermal, conditions. This layer is called the mixed layer. On the low-latitude profile, the mixed layerextends to a depth of approximately how many meters?

40 meters...

Explanation:

At low altitudes, the depth of mixed layer has a layer temperature difference of 0.2 Degrees per layer and that is constant for a mixed first layer that has a depth of 40 meters below surface. As we go  down, the temperature difference of all mixed layer differ by 0.2 degrees every 40 meters...

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia