Newton's kinetic energy vs Planck's Energy?

AI Thread Summary
The discussion explores the relationship between Newton's kinetic energy formula (E=1/2mv²) and Planck's energy formula (E=hv). It highlights that Newton's formula applies to objects with mass, where energy increases exponentially with velocity, while Planck's formula pertains to photons, with energy increasing linearly with frequency. The conversation notes that photons travel at a constant speed, even when their frequency changes due to the Doppler effect. A potential connection between the two formulas is suggested through the photoelectric effect, where photon energy can be related to the kinetic energy of electrons. Understanding these distinctions is crucial for relating the two energy concepts.
lenfromkits
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Formula for energy:

E = hv (where v=frequency; h=Planck's constant)

and

E= 1/2mv2 (New's kinetic energy).

How are these two formulas related? For starters, according to Newton, energy here increases exponentially to velocity, yet for Planck, the increase is linear to the frequency (which in a way is like velocity if you consider that the frequency increases 1:1 with velocity when doppler shifted).

I can't see the real connection between these two formulas. Is there a way to convert between them?

Thanks.
 
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Well you have to understand the Plancks fromula is for photons. Where as Newtons formula is for objects. Next part is that yes velocity is the most determining factor in Newtons law but Photon travel at the speed of light which is constant. It does not ever change even if its doppler shifted. when an a light wave is doppler shifted its frequency changes.

As far as the connection? You can connect the two some how to find the rest mass of a photon... I think...
Another connection is the Photoelectric affect. Where you can calculate the energy of the photon by adding the Kinetic energy of the Electron and its bond energy, which will be equal to E=hv.

Hope that makes sense,
Fox
 

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