Abox with mass m is dragged across a level floor having a coefficient of kinetic friction μk by a rope that is pulled upward at an angle θ above the horizontal with a force of magnitude
f.

answer: b.

explanation:

answer; equivalent to a one(1) horsepower motor;

+15-35=-20

going in opposite directions

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 =