A 0.50 kg croquet ball is initially at rest on the grass. When the ball is truck by a mallet, the average force exerted on ot is 230 N. If the balls speed after being struck is 3.2 m/s, how long was the mallet in contact with the ball?

it may be wrong but i think its a

area of focus

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 =