The mass of an electron is `9.1xx10^(-31)kg`. If its K.E. is `3.0xx10^(-25) J`, calculate its wavelength

Explanation

`K.E = 1/ 2 "mu"^2 ...(1)`
` :. U = h/( n lambda) ...(2) `
By eqs , (1) and (2) ,
` K.E. = 1 /2 m h^2 /( m^2 lambda ^2 ) or lambda = sqrt ( h^2 /( 2 m xx K.E.))`
` :. lambda = sqrt (( 6.626 xx 10^(34) xx 6.626 xx 10^(-34))/( 2xx 9.1 xx 10^(-31) xx 3. 0 xx 10^(-25)))`
` = 8966 xx 10^(-10) m = 8966 Å `.