A physics student does 10 J of work to lift a textbook in .4 seconds. How much power did this generate? a 25 W
b 4 W
c 40 W
d 100 J

f=ma newton

f=100x2.5=250n

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 =