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Units of De Broglie's Equation

Posted: Thu Oct 25, 2018 10:20 pm
by Jack Mitchell 3J
I understand that the SI unit for wavelength is meters, but when doing the calculation, how do you cancel the other units to get meters.

Re: Units of De Broglie's Equation

Posted: Thu Oct 25, 2018 10:28 pm
by pamcoronel1H
Since it is h/mv, and J=kg×m^2 the units are:
(kg×m^2)×s/kg×(m×s)
The kg, s, and one m cancel out, leaving only one m on top, which is your unit for wavelength :)

Re: Units of De Broglie's Equation

Posted: Thu Oct 25, 2018 10:30 pm
by Henry Krasner 1C
Lambda=h/mv
Lambda is in meters
h- Planck's constant (6.63x10^(-34))J s or (kg m^2.s^2) s
m-mass in kg
v- velocity in m.s
Everything cancels out so that Lambda, or wavelength, is just in meters.

Re: Units of De Broglie's Equation

Posted: Thu Oct 25, 2018 10:31 pm
by Yiting_Gong_4L
Wavelength can also be converted from meters to nanometers and written in that unit.

Re: Units of De Broglie's Equation

Posted: Thu Oct 25, 2018 11:31 pm
by Jack Mitchell 3J
Thanks Guys