Question

calculate the kinetic energy associated with a moving electron having de Broglie wavelength of 725nm​

Answer 1

Given - Wavelength - 725 nm

Find - Kinetic energy of moving electron

Solution - To find kinetic energy, formula used will be -

KE = h²/(2*lambda²*mass of electron), where KE is kinetic energy and h is Planck's constant.

Wavelength - 7.25*10^-7 metre

Planck's constant (h) - 6.6*10^-34 m² kg/s

Mass of electron - 9.1*10^-31 kg

Keeping the values in equation-

KE = 6.6*10^-34²/(2*7.25*10^-7²*9.1*10^-31)

KE = 6.6*10^-34²/9.6*10^-43

KE = 4.5*10^-25

Hence, kinetic energy of moving electron will be - 4.5*10^-25 kilogram metre/second²