Solar power is not the best option in some countries because places like Rjukan (Norway) that do not recieve enough sunlight because of where they are located.
The answer is density, temperature, and salinity. These are the factors that makes a current that is 50 meter less deep. The other choices will create a higher amplitude of the current.
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:
Point 3
Explanation:
When contour lines are close together, it indicates a slope that is steeper.
