What should be the velocity of the electron so that its momentum equals of `4000Å` wavelength photon.

Explanation

Given data `:`
Momentum of the electron `p = lambda ` wavelength of photon` = 4000 xx 10^(-10) m` `[ lambda = ( h )/( P ) ]`
P = mass ` xx` velocity `:. P = ( h )/( lambda)`
Mass of electron `= 9.1 xx 10^(-31) kg`
To find `:` `mv = ( .h)/( lambda)`
Velocity of the electron `v= ? `
`v = ( h )/( m lambda) = ( 6.626 xx 10^(-34))/( 0.1 xx 10^(-31) xx 4000 xx 10^(-10)) ` `v = ( h )/( m lambda)`
`= 0.182 xx 10^(4)`
`v = 1820 ms^(-1)`