Astone is dropped from a bridge and hits the pavement below in two seconds. what is the velocity of the stone when it hits the pavement? 0.20 m/s 4.9 m/s 9.8 m/s 19.6 m/s

The final velocity of the stone = 19.6 m/s

Explanation:

We have to find the velocity of a stone dropped from a tower which hits the pavement in two seconds.

As a stone is released from the top of a building , it undergoes uniform acceleration of gravity and speeds up and hits the ground with a certain speed.

We have the equation,

v = u + gt

v = final velocity

u = initial velocity

t = time taken

g = 9.8 m/

Substituting these values we get

v = 0 + 9.8

v = 19.6 m/s

The final velocity of the stone = 19.6 m/s

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 =