How much time a light ray take to reach from earth to moon? (Distance of moon from the earth = 3.5 × 108 m)

Question

How much time a light ray take to reach from earth to moon? (Distance of moon from the earth = 3.5 × 108 m) (A) 2 s (B) 1.4 s (C) 8 min (D) 1.16 s

Tardigrade Admin · Accepted Answer

Here, Speed of light, c = 3 × 108 ms-1 Distance of moon from the earth, D = 3.5 × 108 m Time taken by the light to reach from earth to moon is t=(D/c)=(3.5 × 108 m/3 × 108 ms-1) =1.16 s

Q. How much time a light ray take to reach from earth to moon?
(Distance of moon from the earth $= 3.5 \times 1 0^{8} m)$

$2 s$

$1.4 s$

$8 min$

$1.16 s$

Here,
Speed of light, $c = 3 \times 1 0^{8} m s^{- 1}$
Distance of moon from the earth, $D = 3.5 \times 1 0^{8} m$
Time taken by the light to reach from earth to moon is
$t = \frac{D}{c} = \frac{3.5 \times 1 0 ^{8} m}{3 \times 1 0 ^{8} m s ^{- 1}}$
$= 1.16 s$

Q. How much time a light ray take to reach from earth to moon? (Distance of moon from the earth =3.5×108m)

2s

1.4s

8min

1.16s