Question

A man fires a gun 150m from a cliff. A second man who is standing 300m further away from the cliff hears the gun 1 second after he sees the flash. When will the second man will hear the echo from the cliff?

Answer 1

d = 2 * (150+300) = 900m = Total distance traveled by the sound.

d = Vt,
t = d / V = 900m / 300m/s = 3s. to hear
echo.

Answer 2

d = 2* 150 + 300= 600 m

t=d/v
=600m/300m/s
=2s to hear