When air is blown into the open pipe,
L =
where nis any integral number 1,2,3,4 etc. and λ is the wavelength of the oscillation
⇒λ=
Note here that n=1 is for fundamental, n=2 is first harmonic and so on..
⇒ third harmonic will be n=4
Given L=6m, n=4, solving for λ we get:
λ= =3m
Relationship of frequency(f), velocity of sound (c) and wavelength(λ) is:
c=f.λ Or f=
⇒f=
≈115 Hz
The electrostatic force between the two ions is
Explanation:
The electrostatic force between two charged particle is given by Coulomb's law:
where
is the Coulomb's constant
are the two charges
r is the separation between the two charges
In this problem, the ion of sodium has a charge of
while the ion of chlorine has a charge of
And the distance between the two ions is
Substituting, we find the electrostatic force between the two ions:
where the negative sign simply means that the force is attractive, since the two ions have opposite charge.
Learn more about electrostatic force:
#LearnwithBrainly
To solve this problem it is necessary to apply the concepts related to the Third Law of Kepler.
Kepler's third law tells us that the period is defined as
The given data are given with respect to known constants, for example the mass of the sun is
The radius between the earth and the sun is given by
From the mentioned star it is known that this is 8.2 time mass of sun and it is 6.2 times the distance between earth and the sun
Therefore:
Substituting in Kepler's third law:
Therefore the period of this star is 3.8years