An electron moves in an electric field with a kinetic energy of 2.5 eV. What is the associated de Broglie wavelength?

Explanation

Kinetic energy
`=(1)/(2)mv^(2)(v=(h)/(mlamda))`
`=(1)/(2)m((h)/(mlamda))^(2)`
`=(1)/(2)(h^(2))/(mlamda^(2))`
or `lamda^(2)=(1)/(2)(h^(2))/(mxxKE)`
`lamda=(h)/(sqrt(2mxxKE)){:((m=9.108xx10^(-28)),(h=6.626xx10^(-27)erg-sec),(1eV=1.602xx10^(-12)erg)):}`
`=(6.626xx10^(-27))/(sqrt(2xx9.108xx10^(-28)xx2.5xx1.602xx10^(-12)))`
`=7.7xx10^(-8)cm`.