What is the intensity, in watts per square meter, of a laser beam that is 90.0% absorbed by a 2.15-mm diameter spot of cancerous tissue and must deposit 525 J of energy to it in a time period of 4.2 s?

asthenosphere and convection

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 =

answer(20) psi;