Which best describes pitch? the amount of time taken for a longitudinal wave to produce one cycle
the number of cycles per second perceived by the human ear
the amplitude of a wave when the natural frequency is matched
the distance between two corresponding parts of a transverse wave

v=ir = 3x15 =45 v

pecialized keyboards

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 =