The acceleration of the light travelling in vacuum is ________

Explanation

To determine the acceleration of light traveling in a vacuum, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Acceleration**:
- Acceleration is defined as the rate of change of velocity with respect to time. Mathematically, it is expressed as:
\[
a = \frac{dv}{dt}
...