What is the De Broglie wavelength of

(a) 1 eV electron

(b) 10 MeV proton

(c) 100 MeV electron? (You might need to use the relativistic energy formula for ©

Respuesta :

Answer:

(a). The wave length of 1 eV electron is [tex]1.23\times10^{-9}\ m[/tex].

(b). The wave length of 10 MeV proton is [tex]9.06\times10^{-15}\ m[/tex].

(c). The wave length of 100 MeV electron is [tex]1.23\times10^{-13}\ m[/tex].

Explanation:

Given that,

[tex]E =1\ ev[/tex]

[tex]E=10 MeV[/tex]

[tex]E=100 MeV[/tex]

(a). We need to calculate the wavelength of 1 eV electron

Using formula of De Broglie wavelength

[tex]\lambda=\dfrac{h}{\sqrt{2mE}}[/tex]

[tex]\lambda=\dfrac{6.63\times10^{-34}}{\sqrt{2\times9.1\times10^{-31}\times1\times1.6\times10^{-19}}}[/tex]

[tex]\lambda=1.23\times10^{-9}\ m[/tex]

[tex]\lambda=1.23\ nm[/tex]

The wave length of 1 eV electron is [tex]1.23\times10^{-9}\ m[/tex].

(b). We need to calculate the wavelength of 10 MeV proton

Using formula of De Broglie wavelength

[tex]\lambda=\dfrac{h}{\sqrt{2mE}}[/tex]

Put the value into the formula

[tex]\lambda=\dfrac{6.63\times10^{-34}}{\sqrt{2\times1.67\times10^{-27}\times10\times10^{6}\times1.6\times10^{-19}}}[/tex]

[tex]\lambda=\dfrac{6.63\times10^{-34}}{\sqrt{5.344\times10^{-39}}}[/tex]

[tex]\lambda=9.06\times10^{-15}\ m[/tex]

The wave length of 10 MeV proton is [tex]9.06\times10^{-15}\ m[/tex].

(c). We need to calculate the wavelength of 100 MeV electron

Using formula of De Broglie wavelength

[tex]\lambda=\dfrac{h}{\sqrt{2mE}}[/tex]

Put the value into the formula

[tex]\lambda=\dfrac{6.63\times10^{-34}}{\sqrt{2\times9.1\times10^{-31}\times100\times10^{6}\times1.6\times10^{-19}}}[/tex]

[tex]\lambda=1.23\times10^{-13}\ m[/tex]

The wave length of 100 MeV electron is [tex]1.23\times10^{-13}\ m[/tex].

Hence, This is the required solution.