HELP PLS Using the slide of the dam as an example, as well as the notes on the slide with the field and tractor, describe the different sphere interactions that are occuing in the picture of THE FARM AND TRACTOR. Be sure to be detailed and explicit (use the dam sample as an example).

not too sure thinking it will always be directed towards the centre of the earth. could be wrong not sure

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 =