So 3 x 10^8 / 3 x 10^9 = 0.1 metre = 10 centimetre = okay, 3.9 inches
But then metric always saves your ass. Back in physics class, they'd ask you how deep the well was if you dropped a stone & heard the water splash in 10 seconds. Before the American students could even begin their work, all the Indians would yell "500 metres!" And that's cause the gravitation constant is 10, so one half 10 times 10 times 10 is 500.
Is it just me that finds this suggestion offensive. Maybe the Indians had already thought about that and since they were already taking g as 10 m/sec^2, they thought that the difference because of sound delay would be insignificant. As would be the variability in speed of sound near the water surface due to moisture.
My response was designed to highlight the equally offensive suggestion that "all the Indians" were metric geniuses, while American students were all slow and ignorant of the metric system.
Actually the gravitation constant is 6.67×10^-11 N m^2/kg^2. Gravitational acceleration on earths surface is on average 9.81 m/s^2, and not really a constant (it varies slightly from place to place).
speed of light = 3 x 10^8 m/s
3 GHZ = 3 x 10^9 /s
So 3 x 10^8 / 3 x 10^9 = 0.1 metre = 10 centimetre = okay, 3.9 inches
But then metric always saves your ass. Back in physics class, they'd ask you how deep the well was if you dropped a stone & heard the water splash in 10 seconds. Before the American students could even begin their work, all the Indians would yell "500 metres!" And that's cause the gravitation constant is 10, so one half 10 times 10 times 10 is 500.