Respuesta :
Answer:
1.5 billion years = 3.33 meters
From the end 2.22\times 10^{-5} meters is the distance of written history.
Step-by-step explanation:
Age of earth is 4.5 billion years and we have to represent the history of earth (from birth to present ) with a 10 meter long timeline.
So on the scale every meter will represent 4.5/10 = 0.45 billion years.
∵ 0.45 billion years represent the distance = 1 meter on scale.
∴ 1 billion years will be represented by = [tex]\frac{1}{.45} = \frac{20}{9} meters[/tex]
∴ For 1.5 billion years distance will be = [tex]\frac{20}{9}(1.5) = \frac{30}{9} = 3.33 meters[/tex]
Now we have to measure the length of written history from the end of the timeline.
Since written human history extends about 10000 yrs back means distance on timeline = [tex](\frac{20}{9})(\frac{10^{4} }{10^{9}})[/tex] = [tex]2.22\times 10^{-5} meters[/tex] from the end.
