The threshold wavelength for a metal is 680nm. Calculate the maximum velocity of photoelectrons emitted when radiation of wavelength 560nm is incident on the metal.

Explanation

To solve the problem of calculating the maximum velocity of photoelectrons emitted when radiation of wavelength 560 nm is incident on a metal with a threshold wavelength of 680 nm, we can follow these steps:

### Step 1: Understand the Photoelectric Effect
The photoelectric effect states that when light of sufficient energy (or frequency) hits a metal surface, it can eject electrons from that surface. The energy of the incident light must be greater than the work function of the metal for electrons to be emitted.

### Step 2: Use the Einstein Photoelectric Equation
The Einstein photoelectric equation can be expressed as:
\[ E_{\text{incident}} = KE_{\text{max}} + \phi \]
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