Alight ray traveling in air enters a second
medium and its speed slows to 1.71 × 10^8 meters
per second. what is the absolute index of
refraction of the second medium?
(1) 1.00 (3) 1.75
(2) 0.570 (4) 1.94

radiation

explanation:

heat is transmitted by radiation

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 =