A25-newton weight falls freely from rest from
the roof of a building. what is the total distance
the weight falls in the first 1.0 second?
(1) 19.6 m (3) 4.9 m
(2) 9.8 m (4) 2.5 m

Distance covered, d = 4.9 meters

Explanation:

It is given that,

Force acting on the freely falling object, F = 25 N

Let d is the distance  the weight falls in the first 1.0 second. It can be calculated using the second equation of motion as :

u = 0 here

d = 4.9 meters

So, the distance  the weight falls in the first 1.0 second is 4.9 meters. Hence, this is the required solution.

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers

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 =