The threshold frequency `v_(0)` for a metal is `7.0xx10^(14)s^(-1)` . Calculate the kinetic energy of an electron emitted when radiation of frequency `v=1.0xx10^(15)s^(-1)` hits the metal .

Explanation

According to Einsten 's equation Kinetic energy `=(1)/(2)m_(e)v^(2)=h(v-v_(0))`
=`(6.626xx10^(-34)J S)`
`(1.0xx10^(14)s^(-1)-7.0xx10^(14)s^(-1))`
=`(6.626xx10^(-34)Js)(3.0xx10^(14)s^(-1))`
`=(6.626xx10^(34)Js)(3.0xx10^(14)s^(-1))`
`=1.988xx10^(-19)J`