Question

Suppose you hear a clap of thunder 14.2 s after seeing the associated lightning strike. The speed of light in air is 3.00 108 m/s.
(a) How far are you from the lightning strike? (The speed of sound waves in air is 343 m/s.)

Answer 1

Let:

$$t = 14.2 \, \text{s}$$ $$v = 343 \, \text{m/s}$$ $$v1 = 3.00 \times 10^8 \, \text{m/s}$$ $$S = ?$$ $$S = v \cdot t$$ $$S = 343 \cdot 14.2 = 4870.6 \, \text{m}$$

Answer: You are 4870.6 m from lightning strike. Time for which light has transited this distance too little and it can to be considered.

$$t = \frac{s}{v1} = \frac{4870.6}{3.00 \times 10^8} = 0.008 \, \text{s}$$