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De Broglie Wavelength

Posted: Tue Oct 15, 2019 2:25 pm
When a question asks to calculate the De Broglie Wavelength, does that mean there is a certain wavelength that is specific to De Broglie? I thought it was just an equation to calculate wavelength in general, not a totally different wavelength. But the way some of these questions are worded it has me concerned.

Re: De Broglie Wavelength

Posted: Tue Oct 15, 2019 2:29 pm
So when it asks for the De Broglie Wavelength, you would find the wavelength through h=mvl or l = h/mv

Re: De Broglie Wavelength

Posted: Tue Oct 15, 2019 2:30 pm
I think it just means to use the De Broglie equation because the De Broglie equation is derived from the equations E=pc, c= wavelength*frequency, and E=hv which we have learned before. However, this equation only works for any particle with a rest mass, momentum, and wavelength so if it asks for the De Broglie wavelength, it probably means that these conditions are met.

Re: De Broglie Wavelength

Posted: Wed Oct 16, 2019 5:36 pm
Jordan Young 3E wrote:I think it just means to use the De Broglie equation because the De Broglie equation is derived from the equations E=pc, c= wavelength*frequency, and E=hv which we have learned before. However, this equation only works for any particle with a rest mass, momentum, and wavelength so if it asks for the De Broglie wavelength, it probably means that these conditions are met.

Can you clarify what a "rest mass, momentum, and wavelength" means and how we know if these conditions are met?

Re: De Broglie Wavelength

Posted: Wed Oct 16, 2019 5:41 pm
505106414 wrote:
Jordan Young 3E wrote:I think it just means to use the De Broglie equation because the De Broglie equation is derived from the equations E=pc, c= wavelength*frequency, and E=hv which we have learned before. However, this equation only works for any particle with a rest mass, momentum, and wavelength so if it asks for the De Broglie wavelength, it probably means that these conditions are met.

Can you clarify what a "rest mass, momentum, and wavelength" means and how we know if these conditions are met?

Rest mass and momentum mean that we can only apply the De Broglie equation to particles with mass. This basically means that we are excluding photons, because they do not have rest mass.

Re: De Broglie Wavelength

Posted: Wed Oct 16, 2019 5:43 pm
Does calculating the De Broglie wavelength just mean calculating the wavelength of an electron?

Re: De Broglie Wavelength

Posted: Wed Oct 16, 2019 8:34 pm
The De Broglie wavelength equation is used to see if a moving particle has detectable wavelike properties.

Re: De Broglie Wavelength

Posted: Thu Oct 17, 2019 9:24 am
Jordan Young 3E wrote:I think it just means to use the De Broglie equation because the De Broglie equation is derived from the equations E=pc, c= wavelength*frequency, and E=hv which we have learned before. However, this equation only works for any particle with a rest mass, momentum, and wavelength so if it asks for the De Broglie wavelength, it probably means that these conditions are met.

What does it mean a particle with a "rest mass?" In problems given that require use of the De Broglie equation should we just assume these conditions have been met or is there an alternative way to check?