The inner and outer surfaces of a 4-m × 7-m brick wall of thickness 30 cm and thermal conductivity 0.69 w/m-k are maintained at temperatures of 20 °c and 5 °c, respectively. determine the rate of heat transfer through the wall, in w.

Explanation:

As we know that the rate of heat transfer due to temperature difference is given by the formula

here we know that

A = 4 m x 7 m

thickness = 30 cm

temperature difference is given as

now we have

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray