How far does light travel in the time it takes sound to travel 1 cm in air at 28°C?

Question

How far does light travel in the time it takes sound to travel 1 cm in air at 28°C?

Answer 1

Generally, we can say the speed of sound in air is:

V_sound = 331.4 + 0.6•T_C so V_{sound ar 28°C} = 331.4 + 0.6•28 = 348.2 m/s

To travel 1 cm or 0.01 m, we could say v = d/t or t = d/v = 0.01/348.2 = 2.8719 x 10^-5 seconds

Light travels at 299,792,458 m/s so to find out how far it travels in 2.8719 x 10^-5 seconds we can say d = vt or d = (299,792,458)(2.8719 x 10^-5) = 8610 meters or, using 1 significant figure, d = 9 km