How long does it take light to travel 300 km in a vacuum?

Answer 1

Answer #1:

To calculate the distance that light travels in water, we need velocity and time.

Velocity and time will enable us to correctly compute the distance.

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Answer #2:

The "refractive index" of water is around 4/3 (look up). This tells us that . . .

-- the speed of light in water is about 3/4 of its speed in vacuum;

-- the time it takes light to cover a distance in water is 4/3 the time it would take

in vacuum;

-- the distance light can cover in water is about 3/4 the distance it can cover

in the same length of time in vacuum.

In whatever time it takes light to travel 1.0 meter in vacuum, it can travel

only about 75 cm in water.

Answer 2

Speed of light in a vacuum is c = 299 792 458 m/s.

To travel the distance of d meters, it would take light t = d / c seconds.

Therefore, if d = 1 m, then:

t = 1 / 299792458 s ~= 3.3356 * 10^-9 s = 3.3356 ns

It would take light approximately 3.3356 nanoseconds to travel one meter in a vacuum.

Answer 3

1/299792458 of a second, by the definition of one meter.

Answer 4

299,792.458 kilometers (186,282.397 miles)

Answer 5

1 meter / 300,000,000 meters/second; approximately 3.3 nanoseconds.

Answer 6

Not long, just 0.00100069 seconds.

Answer 7

0.4137 (rounded)

Answer 8

3.3356