The momentum (in `kg-m//s)` of photon having 6 MeV energy is :

Options

A. (a) `3.2xx10^(-21)`
B. (b) `2.0`
C. (c) `1.6xx10^(-21)`
D. (d) none of these

Answer

To find the momentum of a photon with an energy of 6 MeV, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the relationship between energy and momentum for a photon**:
The energy \( E \) of a photon is related to its momentum \( p \) by the equation:
\[ p = \frac{E}{c} \]
where \( c \) is the speed of light.

2. **Convert the energy from MeV to Joules**:
The energy given is 6 MeV. We need to convert this to Joules. The conversion factor is:
\[ 1 \text{ eV} = 1.6 \times 10^{-19} \text{ Joules} \]
Therefore, for 6 MeV:
\[ E = 6 \times 10^6 \text{ eV} \times 1.6 \times 10^{-19} \text{ J/eV} = 9.6 \times 10^{-13} \text{ J} \]

3. **Use the speed of light**:
The speed of light \( c \) is approximately:
\[ c = 3 \times 10^8 \text{ m/s} \]

4. **Calculate the momentum**:
Now, substitute the values of energy and speed of light into the momentum formula:
\[ p = \frac{E}{c} = \frac{9.6 \times 10^{-13} \text{ J}}{3 \times 10^8 \text{ m/s}} \]
Performing the calculation:
\[ p = 3.2 \times 10^{-21} \text{ kg m/s} \]

5. **Final Result**:
The momentum of the photon is:
\[ p = 3.2 \times 10^{-21} \text{ kg m/s} \]