According to newton’s law of gravity, which of the following is inversely related to the square of the distance from earth? a. mass b. weight c. gravitational constant d. distance

B. Weight

Explanation:

If you look at my crude drawing of two bodies attracted by each other (hey that's gravity, not love!) and to Newton's law of gravity:

For this to work we have to assume that the Forces are equal and the whole system is in equilibrium.

Now if we take a look at the picture, r is the distance between the two bodies, G is the gravitational constant, and m is the mass either of body 1 or 2, so, if we increase the distance, the force of gravity will decrease by the square root of that unit, because it is the denominator of the fraction.

Now emphasis on "Force of Gravity" Force is the only factor inversely proportionate to the square root of the distance, and the only answer that is actually a Force from the options is weight (m*g).

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 =