- #1
Domnu
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Problem
A harmonic oscillator consists of a mass of [tex] 1 g[/tex] on a spring. Its frequency is [tex]1 Hz[/tex] and the mass passes through the equilibrium position with a velocity of [tex]10 cm/s[/tex]. What is the order of magnitude of the quantum number associated with the energy of the system?
Solution?
Okay, so the eigenenergies associated with a harmonic oscillator are of the form
So, here, we have that [tex]\omega_0 = 2\pi Hz[/tex]. Now, we know that the energy of the system is (nonrelativistically, because the speeds are very small...)
Now, we equate this with the eigenenergy formula, which gives us that the quantum number, [tex]n = 7.54594 \cdot 10^{27}[/tex], which is a ridiculously large number. So the magnitude would be [tex]\box{27}[/tex]. Now I am guessing that such a large order of magnitude is fine since a one gram object (which is decently sized... say the density of water) in quantum mechanics is massive (like the size of the sun, compared to us). Is my answer, and more importantly, my method, correct?
A harmonic oscillator consists of a mass of [tex] 1 g[/tex] on a spring. Its frequency is [tex]1 Hz[/tex] and the mass passes through the equilibrium position with a velocity of [tex]10 cm/s[/tex]. What is the order of magnitude of the quantum number associated with the energy of the system?
Solution?
Okay, so the eigenenergies associated with a harmonic oscillator are of the form
[tex]E_n = \hbar \omega_0 \left (n + \frac{1}{2}\right)[/tex]
So, here, we have that [tex]\omega_0 = 2\pi Hz[/tex]. Now, we know that the energy of the system is (nonrelativistically, because the speeds are very small...)
[tex] 1/2 m v^2 = 5 \cdot 10^{-6} J[/tex]
Now, we equate this with the eigenenergy formula, which gives us that the quantum number, [tex]n = 7.54594 \cdot 10^{27}[/tex], which is a ridiculously large number. So the magnitude would be [tex]\box{27}[/tex]. Now I am guessing that such a large order of magnitude is fine since a one gram object (which is decently sized... say the density of water) in quantum mechanics is massive (like the size of the sun, compared to us). Is my answer, and more importantly, my method, correct?