In 1924, Louis de Broglie postulated that particles such as electrons and proton
ID: 2301189 • Letter: I
Question
In 1924, Louis de Broglie postulated that particles such as electrons and protons might exhibit wavelike properties. His thinking was guided by the notion that light has both wave and particle characteristics, so he postulated that particles such as electrons and protons would obey the same wavelength-momentum relation as that obeyed by light: lambda = h/p, where lambda is the wavelength, p the momentum, and h Planck's constant.
Find the de Broglie wavelength lambda for an electron moving at a speed of 1.00 imes 10^6 ; { m/s}. (Note that this speed is low enough that the classical momentum formula p=mv is still valid.) Recall that the mass of an electron is m e = 9.11 imes 10^{-31}; { kg}, and Planck's constant is h = 6.626 imes 10^{-34}; J s.
Find the de Broglie wavelength lambda of a baseball pitched at a speed of 44.3 m/s. Assume that the mass of the baseball is 0.143 ;kg}. answer in meters
***What is the momentum p of one of these electrons?
Explanation / Answer
a> for electron:-
lambda = h/mv = (6.626 * 10-34)/ (9.11 *10-31 * 1 * 106) = 7.27 * 10-10 m
b> for ball :-
lambda = (6.626 *10-34)/ (0.143 * 44.3) = 1.046 *10-34 m
momentum of electron = mv = (9.11 * 10-31)*(1* 106) =9.11 * 10-25 kg m/s