Their Period number is common means their "Principal Quantum Numbers" are same
Hope this helps!
Data:

n (Wave node)
V (Wave belly)
L (Wave length)
<span>The number of bells is equal to the number of the harmonic emitted by the string.
</span>

Wire 2 → 2º Harmonic → n = 2







Wire 1 → 1º Harmonic or Fundamental rope → n = 1



If, We have:
V = 42L
Soon:



Answer:
<span>The fundamental frequency of the string:
</span>
21 Hz
The age of the galaxy when we look back is 13.97 billion years.
The given parameters:
- <em>distance of the galaxy, x = 2,000 Mpc</em>
According Hubble's law the age of the universe is calculated as follows;
v = H₀x
where;
H₀ = 70 km/s/Mpc

Thus, the age of the galaxy when we look back is 13.97 billion years.
Learn more about Hubble's law here: brainly.com/question/19819028
. . . 'protect' its domestic steel industry, by
increasing the price of imported steel.
Answer:
period
Explanation:
A wave takes 0.5 seconds to complete one cycle. It is called the time period of the wave. It is the time taken by the wave to complete one cycle.
The relation between the time period and the frequency is given by :
T = 1/f
Where
f is frequency of the wave
Hence, the correct option is (a) "period".