The earth has a radius of 6.38 × 106 m and turns on its axis once every 23.9 h.

(a) what is the tangential speed (in m/s) of a person living in ecuador, a country that lies on the equator?

(b) at what latitude (i. e., the angle theta in the drawing) is the tangential speed one-third that of a person living in ecuador?

a) V = 465.9 m/s

b) θ = 70.529°

Explanation:

Let's first calculate angular velocity of earth:

Velocity of a person on Ecuador will be:

For part b, since angular velocity is the same:

Solving for θ:

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 =