If a metal wire is 4m long and a force of 5000n causes it to stretch by 1mm, what is the strain?

Explanation:

The strain is defined as the ratio of change of dimension of an object under a force:

where

is the change in length of the object

is the original length of the object

In this problem, we have and , therefore the strain is

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 =