Hydrogen atom travelling with a constant speed v collides with a photon of wavelength 200 nm , travelling in opposite direction and comes to rest . Calculate the value of v. Assume that entire energy of photon is absorbed by the hydrogen atom.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Calculate the energy of the photon
The energy \( E \) of a photon can be calculated using the formula:
\[ E = \frac{hc}{\lambda} \]
where:
...