At a temperature of 15gr, the speed of sound in air = 340m / s. when fired from a gun, the bullet flies

At a temperature of 15gr, the speed of sound in air = 340m / s. when fired from a gun, the bullet flies at an average speed of 800 m / s. How many seconds will the sound of a shot lag behind a bullet that has flown 1.20 km?

1) Calculate the time for sound to travel a distance of 1.2 km (1200 m):

t1 = S / V1, where V1 is the speed of sound at a temperature of 15 ºС (V1 = 340 m / s).

t1 = 1200/340 = 3.53 s.

2) Calculate the time a bullet travels a distance of 1.2 km (1200 m):

t2 = S / V2, where V2 is the speed of the bullet when fired from the gun (V2 = 800 m / s).

t2 = 1200/800 = 1.5 s.

3) Calculate the sound lag from the bullet:

t = t1 – t2 = 3.53 – 1.5 = 2.03 s.

Answer: The sound will lag behind the rifle bullet by 2.03 s.