6 ms·
Didn't get any of that so had to redo in metric. 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,
by dxbydt 15y ago
Didn't get any of that so had to redo in metric.
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.
- abecedarius 15y agoGenerally agreed, but for this case I remember the speed of light as a foot per nanosecond, and the arithmetic is just dividing 12 by 3.
- narkee 15y agoMaybe the Americans were busy incorporating the delay due to the finite speed of sound.
- rrrazdan 15y agoIs 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.
- narkee 15y agoMy 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.
- fckin 15y agoToo bad the gravitation constant is 9.8
- zokier 15y agoActually 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).
- garindra 15y agoRelevant : http://www.quora.com/Why-does-gravitational-acceleration-differ-at-different-places-on-earth http://www.quora.com/Why-does-gravitational-acceleration-dif...