Modern lasers can create a pulse of light that lasts only a few femtoseconds. (1 fs = 1 x 10-15 s).
What is the length of a pulse of light that lasts 6.0 fs?

A light ray travels basically 300 000 000 m in one second. That makes (300 000 000/1E-15) in one fs. Then, multiply by 6 to get the distance.

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