An object of mass is used to provide tension in a 6.0 ‑m‑long string that has a mass of 0.252 kg, as shown. A standing wave that has a wavelength equal to 1.5 m is produced by a source that vibrates at 24 Hz.

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 =