Saved Bookmarks
| 1. |
The work function of tungsten is 4.50 eV. Calculate the speed of the fastest electron ejected from tungsten surface when electromagnetic radiation of energy 6 eV is incident on the surface. |
|
Answer» SOLUTION :DATA: `Phi = -4.50 eV= 4.50 xx 1.6 xx 10^(-19) J = 7.2 xx 10^(-19) J, hv=6eV = 6 xx 1.6 xx 10^(-19) J = 9.6 xx 10^(-19) J, m=9.1 xx 10^(-31)` kg `1/2mv_("max")^(2) = hv- Phi` `therefore v_("max") = sqrt((2(hv-Phi))/(m)) = [(2(9.6 xx 10^(-19) - 7.2 xx 10^(-19)))/(9.1 xx 10^(-31))]^(1//2)` `=(4.8/9.1)^(1/2) xx 10^(6) m//s = 7.263 xx 10^(5) m//s` This gives the SPEED of the fastest electron ejected from TUNGESTEN surface. |
|