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?
d = 2* 150 + 300= 600 m
t=d/v
=600m/300m/s
=2s to hear
To find out when the second man will hear the echo from the cliff, let's first understand the time it takes for sound to reach him from the gun and the time it takes for sound to reach him from the cliff.
Given:
Distance from the gun to the second man = 150m + 300m = 450m
Time delay between seeing the flash and hearing the gun = 1 second
To calculate the time it takes for the sound to reach the second man from the gun, we can use the formula:
Time = Distance / Speed
The speed of sound in air is approximately 343 meters per second.
Time taken for sound from the gun to reach the second man = 450m / 343 m/s = 1.31 seconds (approximately)
Now, to calculate the time it takes for the sound to reach the second man from the cliff, we need to consider that the sound has to travel the extra distance from the cliff to the second man.
According to the given information, the second man hears the gun 1 second after seeing the flash. This means he hears the sound 1.31 seconds after seeing the flash, as calculated earlier.
So, the second man will hear the echo from the cliff when the sound from the cliff reaches him after the initial sound from the gun. Therefore, he will hear the echo approximately 1.31 seconds after hearing the sound of the gun.
d = 2 * (150+300) = 900m = Total distance traveled by the sound.
d = Vt,
t = d / V = 900m / 300m/s = 3s. to hear
echo.