Superposition is the geologic principle which explains why the bottom stratum in a section of rock is the oldest. The word literally means placing one thing on top of another where the lower strata are the older.
The waves crash into the sand, sometimes creating dunes, and it can also wash some sand out into the ocean. Hope this helps!
Answer:
They grow
Explanation:
they grow from air, water, energy and sun
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.
