Saturday, February 04, 2006

The Age of the Universe - Scientific Notation and Significant Figures

Significant Figures and Scientific Notation

The age of the universe is believed to be approximately 14 billion years. Assuming two significant figures, write the age of the universe in (a) years and (b) seconds, in correct scientific notation.

a) 1.4x1010 years

b) 1.4x1010 years * 365.24 days/year *1440 minutes/day * 60 seconds/minute

= 4.41794304x1017

However, we only have two significant figures (even though we used a number of numbers that have more significant figures – numbers like the seconds per minute have, by definition, an infinite number of significant figures, as there are exactly 60 seconds per minute.

= 4.4x1017 seconds

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