How many nanoseconds does it take light to travel 1.00 ft in a vacuum?

Answer 1

I've heard "one nano for one foot" but never checked it out. Let's do that now: 1 mile = 5,280 feet Speed of light = 186,282 miles per second = (186,282 x 5,280) = 983,568,960 feet per second. One nanosecond = 1 x 10-9 second. Speed of light = 0.9835+ feet per nanosecond You asked for the reciprocal = 1.0167 ns per foot (rounded) It looks like "one nano for one foot" is a pretty good approximation ! If given speed of light in terms of meters first: 299,732,458 m/s (100cm/1m)(1"/2.54cm)(1'/12")(10^-9) > we get (after canceling units) .983374206 1'/s >we need the answer in s not 1/s so we take the reciprocal: (.983374206 1'/s) -1 >we have now satisfied the problem with a solution of 1.01690688 ns/1' My answer is not rounded because of significant digits The units in the conversion above were exact so we should use the 9 significant digits we started with. (please correct if needed)

Answer 2

The speed of light in vacuum corresponds to 299.8 millimeters, or 11.8 inches, per nanosecond.

As engineers, expected to be able to recognize and work with "close enough" figures,

we often use "1 nanosecond = 1 foot."

Answer 3

In a vacuum, it travels 299.792458 millimeters

That's 11.8 inches, and one handy rule that engineers often keep

on their approximate thumb is " 1 ns = 1 foot ."

Answer 4

A beam of light travels 5 feet in one nanosecond.

Answer 5

Light travels 299.792458 millimeters in 1 nanosecond

Here's a handy mnemonic: "1 light-nanosecond = 1 foot" is only about 1.6% off.

Answer 6

In a vacuum, light will travel 300,000 km per second. "On Earth"... well, it really depends what light travels through. In air, it would go almost as fast as in a vacuum.

Answer 7

It would travel approx 300,000,000 metres, except that this distance is far greater than the size of the earth.

Answer 8

1 light nanosecond = 0.299792458 meter

Answer 9

983,568,980 feet per seconds