A wave will travel only as long as it has energy to carry. The energy makes a wave travel and it will stop traveling as soon as the energy is dissipated.
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.
A. Basins are the landforms that are most likely to have coal, oil and gas deposits. Much of the countries natural gas, oil and coal are deposited in the bottom of basins.
I believe that the answer is 7
Granite<span>, </span>diorite<span>, </span>syenite<span>, </span>andesite<span>, and </span>rhyolite<span>. It is also found in metamorphic rocks such as </span>gneiss<span> and </span>schist<span>.</span>
