It would be "Double replacement".
Hope this helps!
Answer:
Population inversion, in physics, the redistribution of atomic energy levels that takes place in a system so that laser action can occur. Although absorption and emission of energy is a continuous process, the statistical distribution (population) of atoms in the various energy states is constant. ...
laser inversion is photon that can stimulate the production of other photons of exactly the same wavelength because of stimulated emission of radiation.
Explanation:
Answer:
The angular frequencies of all the 3 pendulums shall be same.
Explanation:
The time period of a simple pendulum with the approximation
is given by:

The angular frequency
is given by

As we can see that the angular frequency is independent on the initial angle (valid strictly for small angle approximations) we conclude that the angular frequencies of the 3 pendulums are the same.
Answer:

Explanation:
As we know that the level of intensity is given as

here we know



now the sound is travelling in all possible directions so we have



now for level of sound we have

