Compare the wavelengths of an electron (mass = 9.11 x 10⁻³¹ kg) and a proton (mass = 1.67 x 10²⁷ kg), each having (a) a speed of 3.4 x 10⁶ m/s; (b) a kinetic energy of 2.7 x 10⁻¹⁵ J.

Respuesta :

Answer:

Part A:

For electron:

[tex]\lambda_e=2.1392*10^{-10} m[/tex]

For Proton:

[tex]\lambda_p=1.16696*10^{-13} m[/tex]

Part B:

For electron:

[tex]\lambda_e=9.44703*10^{-12} m[/tex]

For Proton:

[tex]\lambda_p=2.20646*10^{-13} m[/tex]

Explanation:

Formula for wave length λ is:

[tex]\lambda=\frac{h}{mv}[/tex]

where:

h is Planck's constant=[tex]6.626*10^{-34}[/tex]

m is the mass

v is the velocity

Part A:

For electron:

[tex]\lambda_e=\frac{6,626*10^{-34}}{(9.11*10^{-31})*(3.4*10^6)} \\\lambda_e=2.1392*10^{-10} m[/tex]

For Proton:

[tex]\lambda_p=\frac{6,626*10^{-34}}{(1.67*10^{-27})*(3.4*10^6)} \\\lambda_p=1.16696*10^{-13} m[/tex]

Wavelength of proton is smaller than that of electron

Part B:

Formula for K.E:

[tex]K.E=\frac{1}{2}mv^2\\v=\sqrt{2 K.E/m}[/tex]

For Electron:

[tex]v_e=\sqrt{\frac{2*2.7*10^{-15}}{9.11*10^{-31}}} \\v_e=76990597.74\ m/s[/tex]

Wavelength for electron:

[tex]\lambda_e=\frac{6,626*10^{-34}}{(9.11*10^{-31})*(76990597.74)} \\\lambda_e=9.44703*10^{-12} m[/tex]

For Proton:

[tex]v_p=\sqrt{\frac{2*2.7*10^{-15}}{1.67*10^{-27}}} \\v_p=1798202.696\ m/s[/tex]

Wavelength for proton:

[tex]\lambda_p=\frac{6,626*10^{-34}}{(1.67*10^{-27})*(1798202.696)} \\\lambda_p=2.20646*10^{-13} m[/tex]

Wavelength of electron is greater than that of proton.