4. What will happen to the force between two charges if the distance between them is
quadrupled? If the original force was 10N,
what will the new force be?

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

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 =

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000