What is the best description of the destructive interference of light?

a. a mechanical wave meets an electromagnetic wave

b. two waves have displaced in opposite directions

c. two waves have the same direction of displacement

d. a longitudinal wave meets a transverse light wave

(it is b)

B. Two waves have displaced in opposite directions

Explanation:

Interference occurs when two waves meet at a point in space. When this occurs, two extreme conditions can occur:

- if the two waves are in phase (=displacement in the same direction), the amplitude of the resultant wave is equal to the sum of the amplitudes of the two waves:

A = A1 + A2

and this condition is called constructive interference

- if the two waves are in anti-phase (=displacement in opposite directions), the amplitude of the resultant wave is equal to the difference of the amplitudes of the two waves:

A = |A1 - A2|

and this condition is called destructive interference. Note that if A1=A2, the amplitude of the resultant wave is zero.

the temperature in kelvin of 2.0 dm3 of an ideal gas is doubled and its pressure is increased by a factor of four. what is the final volume of the gas

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 =