The temperature distribution across a wall 0.2 m thick at a certain instant of time is , where is in degrees celsius and is in meters, 200°c, -180°c/m, and 30°c/m2. the wall has a thermal conductivity of 1 w/m·k. (a) on a unit surface area basis, determine the rate of heat transfer into and out of the wall and the rate of change of energy stored by the wall. (b) if the cold surface is exposed to a fluid at 100°c, what is the convection coefficient?

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =