Answer :
Answer: 258.3 s
Explanation:
The speed [tex]s[/tex] is given by the following equation:
[tex]s=\frac{D}{t}[/tex]
Where:
[tex]s=3(10)^{8} m/s[/tex] is the speed of light in vacuum
[tex]D=2(38776106 km \frac{1000 m}{1 km})=7.75(10)^{10} m[/tex] is the double of the distance between Earth and Moon, since the beam of light travels from Earth to the Moon and back to Earth again.
[tex]t[/tex] is the time it takes to the beam of light to travel the mentioned distance
Isolating [tex]t[/tex] and solving with the given information:
[tex]t=\frac{D}{s}[/tex]
[tex]t=\frac{7.75(10)^{10} m}{3(10)^{8} m/s}[/tex]
Finally:
[tex]t=258.3 s \approx 258 s[/tex]