Saved Bookmarks
| 1. |
To emit a free electron from a metal surface a minimum amount of energy must be supplied. When light of frequency 7.21xx10^14 Hz is incident on a metal surface, the maximum speed of the ejected electrons is 6xx10^5 ms^-1. Calculate the threshold frequency for the metal. |
| Answer» SOLUTION :`hV=hV_0+1/2mv^2 or V_0=V-1/2(mV^2)/H=(7.21xx10^14)-1/2[9.1xx10^-31xx((6xx10^5))^2/(6.626xx10^-34))=4.74xx10^14 HZ` | |