
Frequency, f, is how many cycles of an oscillation occur per second and is measured in cycles per second or hertz (Hz). The period of a wave, T, is the amount of time it takes a wave to vibrate one full cycle. These two terms are inversely proportional to each other: f = 1/T and T = 1/f.

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Answer:
when an electron made a transition from an outer orbit to one closer to the nucleus
Explanation:
Bohr amended that view of the motion of the planetary electrons to bring the model in line with the regular patterns (spectral series) of light emitted by real hydrogen atoms. ... Light, he proposed, radiated from hydrogen atoms only
Answer:
F - fr = ma
, N - W = 0
Explanation:
In this exercise we are asked to identify the forces that act on the jack, for this we will use Newton's second law
On the x axis
We have two forces: the friction and the force of the girl who pulls the cat
F - fr = ma
On the y axis
There are two forces: normal and weight
N - W = 0
A diagram of these forces can be seen in the attachment