Conduction and convection both require some material substance
to move heat from one place to another, and there's none of that
between the sun and Earth.
The only way for thermal energy to move from place to place with
nothing in between is by the process of radiation, and that's how
it gets here from the sun.
Answer:
The submerged effective density is 86.93 kN/m³ or 8.693 Mg/m³
Explanation:
Given;
wet density of soil sample = 2.5 Mg/m³ = 25 kN/m³
Specific gravity of solid particle = 2.7
The dry unit weight of soil;

for undisturbed state, the volume of the soil is;


Submerged effective density is given as;

density of water (ρw) = 2.7 x 25 kN/m³ = 67.5 kN/m³, substitute this in the above equation;

Therefore, the submerged effective density is 86.93 kN/m³ or 8.693 Mg/m³
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