4 ms·
The speed of light is 3×10^8 m/s or 0.3 m/ns (accurate to 0.07%). The speed of sound is 343 m/s at 20°C, or 1 km in 3 seconds (accurate to 3%) Both of these ar
by perilunar 4y ago
The speed of light is 3×10^8 m/s or 0.3 m/ns (accurate to 0.07%). The speed of sound is 343 m/s at 20°C, or 1 km in 3 seconds (accurate to 3%)
Both of these are just as easy to remember.
ft/ns and ft/ms seem pretty useless to me. I guess they work for room-sized things, but go outside and you're converting to miles anyway.