A body is dropped from a height of 30m. What is the velocity of the body after it has covered a distance of 20 m? (Given g= 10 m/s 2) please fast

approximately 19.8  m/s

If using g = 10 m/s^2, the answer rounds to 20 m/s

Explanation:

You can use the kinematic formula that relates distance covered, velocities and acceleration (without time dependence) given by:

which in our case becomes:

If using g = 10 m/s^2, the answer is 20 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 =

you get 2.3=1.21*\frac{a}2 or 4.6=1.21a or a=3.802 (b)

explanation: