Answer: 10, 100
Explanation:
Magnitudes are based on a logarithmic scale (base 10). For each whole number you go up, the amplitude of the ground motion recorded by a seismograph goes up ten times. Using this scale, a magnitude 5 earthquake would result in ten times the level of ground shaking as a magnitude 4 earthquake (and 32 times as much energy would be released).
1 unit increase corresponds to 10 fold increase in magnitude.
Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
Answer:
Provide a global heat balance, Bring rainfall, Replenish Barrier islands, Break up bacteria and Redtide
Explanation:
https://en.wikipedia.org/wiki/Western_Roman_Empire
Answer:
The axis to tilt in a different direction every 26,000 years
