A factory whistle blows at a frequency of 1216 HZ. What pitch will the passengers of a car moving at 8 m/s away from the whistle hear if the speed of sound is 343 m/s.
1315 Hz
1324 Hz
1188 Hz
1117 Hz

lol

explanation:

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 =