3 - University Physics with Modern Physics

Question

Question: How many nanoseconds does it take light to travel 1.00 ft in vacuum? (This result is a useful quantity to remember.)?

 

Step-by-Step Solution

Answer

Answer

 

Light takes 1.016 nanoseconds to travel 1 ft distance in vacuum.

Step 1: Speed of light in vacuum

When light travels through the vacuum, it has the maximum speed. The speed of light in a vacuum is 3x10⁸ m/s. No object in the universe can travel more than this speed.

 

Given data:

The distance traveled in vacuum is d = 1 ft.

The speed of light in vacuum is v=3x10⁸ m/s.

Step 2: Calculation of time in nanoseconds

Since, formula of speed of light is the ratio of distance traveled by the light to the time taken to travel that distance. 

 $\begin{array}{c}v=\frac{d}{t}\\ 3\times {10}^8\text{\hspace{0.17em}m/s}=\frac{\text{1\hspace{0.17em}ft}\times \frac{\text{0.3048\hspace{0.17em}m}}{\text{1\hspace{0.17em}ft}}}{t}\\ t=1.016\times {10}^{-9}s\times \frac{\text{1\hspace{0.17em}ns}}{{\text{1×10}}^{\text{-9}}\text{\hspace{0.17em}s}}\\ t=1.016\text{\hspace{0.17em}ns}\end{array}$

 

Hence from the above calculation it seems light takes 1.016 nanoseconds to travel 1 ft distance in vacuum.