Liquid helium is stored at its boiling-point temperature of 4.2k
in a spherical container (r = 0.404 m). the container isa
perfect blackbody radiator. the container is surrounded by
aspherical shield whose temperature is 86.8 k. a vacuum exists
inthe space between the container and shield. the latent heat
ofvaporization for helium is 2.1 x 104 j/kg. what mass
ofliquid helium boils away through the venting valve in
15.5hours?

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 =

answergravity;