The winner of the drag race shown in Figure 3.3 was traveling with a speed of 140.3 m/s (313.9 mph) at the end of the quarter-mile course. The car started from rest and had an average acceleration of 30.4 m/s/s. What was the winning time for this race?

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 =