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Confusion with the definition of unit of time and distance.

Ram Kishore Bajpai asked: (The question is posted as such without rectifying errors.)

“Why is the time defined by distance traveled by light in vacuum 1/299,452,758?
Why does the people use a easier number such as 1/300,000,000? Why didn’t 1 second?”

It seems that you are confused a little.

The distance traveled by light in vacuum in 1/299,452,758 of a second is defined as one metre. This is because light travels 299,452,758 m in one second in vacuum.

The value 299,452,758 m/s is the speed of light calculated by various experiments and universally accepted standard.

But ordinary situations do not demand this much level of accuracy. If you correct the value 299,452,758 m/s to 1 decimal accuracy, you will get 3.0 x 108 m/s  (3,00,000 m/s) and is used in ordinary calculations requiring one or two decimal places accuracy.

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