Chapter 4, Problem 42A

Light travels in a straight line at a constant speed of 300,000 km/s. What is the light’s acceleration?

To determine

The acceleration of light if it travels at a constant speed of $300,000\text{km/s}$ .

Answer to Problem 42A

Zero

Explanation of Solution

Introduction:

The acceleration acting on an object is given by,

  $\text{acceleration}=\frac{\text{change in velocity}}{\text{time taken}}$

If the light is travelling at a constant speed in a straight line, then change in velocity of the light will be zero and thereby the acceleration of the light will be zero.

Conclusion:

Hence, considering the known formula, the acceleration of the light will be zero.