The mass of an electorn is `9.1xx10^(-31)` Kg.If its Kinetic energy is `3.0xx10^(-25)J`,calculate its wavelength.

Explanation

Step I. Calculation of the velocity of elctron
Kinetic energy`=1/2mv^(2)=3.0xx10^(-25)J=3.0xx10^(-25)Kgm^(2)s^(-2)`
`v^(2)=(2xxK.E)/(M)=(2xx(3.0xx10^(-25)kGm^(2)s^(-2))/((9.1xx10^(-31)Kg))=65.9xx10^(4)m^(2)s^(-2))`
`v=(65.9xx10^(4)m s^(-2))(1/2)=8.12xx10^(2)ms^(-1)`
Step II. Calulation of wavelength of the electron according to de Broglie.s equation,
`gamma=h/(mv)=((6.626xx10^(-34)kgm^(2)s^(-1)))/((9.1xx10^(-31)kg)xx(8.12xx10^(2)ms^(-1)))`
`=0.08967xx10^(-5)m=8967xx10^(-10)m=8967A( :.1A=10^(-10)m)`