An 80 pound and 25 ft metal rod is propped up on a rough floor against a frictionless wall in a state of static equilibrium. The center of mass of the rod is located 10 ft up the rod from the bottom. With what magnitude of forces does the vertical wall push against the rod

1 a

2 b

3 b

4 d

5 d

6 d

explanation:

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 =

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.