Question

what s the work function of the metal if the light of wavelength 4000A generates photoelectron of velocity 6x10^5 from it​

Answer 1

Answer:

Mass of electron is = 9.1 * 10^-31 kg

velocity = 6 * 10^5 m/s

ke = 12/mv^2

=1/2 * 9.1 * 10^-31 * (6 * 10 ^5)^2

= 162 * 10^-21 j

the energy of photo electron is

12400/4000

=3.1 eV

E = Ф +ke

3.1 = Ф + 1

Ф = 2.1 eV

hope it helps !!!!!!!!!

Answer 2

The work function of the metal if the light of wavelength 4000A generates photo electron of velocity 6x10^5 m/s from it​ is 2.1 eV.

• The energy of light is equal to hc/λ, this can be written as 12420/λ(in A)
• So, substituting the values the energy of light is equal to 3.1 eV.
• The kinetic energy of the photo electron produce is equal to mv²/2e eV.substituting the values we get , kinetic energy of the photo electron produced to be 1eV.
• The work function of the metal is the difference between the total energy and the kinetic energy. hence, it is equal to 2.1 eV.
• h=6.62*10^-34 Js; c= 3*10^8 m/s; m=9.1*10^-31 kg; e=1.6*10^-19 C.