Question

About how far apart must you hold your hands for them to be separated by $\mathbf{1}\mathbf{.}\mathbf{0}\mathbf{}\mathbf{}\mathbf{nano}\mathbf{}\mathbf{light}\mathbf{}\mathbf{second}$(the distance light travels in$\mathbf{1}\mathbf{.}\mathbf{0}\mathbf{}\mathbf{ns}$)?

Short answer

One nano light second is equal to $0.30\mathrm{m}$.

Step-by-step solution

Listing the given quantities

Velocity of light, $c=3\times {10}^8\mathrm{m}/\mathrm{s}$

Time period$t=1\mathrm{ns}=1\times {10}^{-9}\sec$

Understanding the concepts of velocity and distance

Using the velocity of light in air, we can find the distance traveled by the light in air in the given time.

Formula:

$d=c\times t$

Calculations of the distance traveled in the given time

$\begin{array}{rcl}d& =& c\times t\\ & =& \left(3\times {10}^8\mathrm{m}/\mathrm{s}\right)\times \left(1\times {10}^{-9}\text{s}\right)\\ & =& 0.30\mathrm{m}\end{array}$

The distance traveled in the given time is $0.30\mathrm{m}$