Answer
$0.30$ m
Work Step by Step
We will use the following formula here;
$$v = \frac{\Delta x}{\Delta t}$$
Rearranging this formula, $$\Delta x = v \Delta t$$
Using $v=3.0 \times 10^8$ m/s, $\Delta x$ is equal to $$\Delta x = (3.0 \times 10^8 m/s)(1.0 \times 10^{-9} s)=0.30m$$
