I think it’s c bc it say one way to make the earths coal supply last longer and you can build and use solar power plants
A=P(1/2)^(t/h)
A=final amount
P=initial amount
t=time
h=half life
so
h=1.3 billlion (just write 1.3 and remember to mulipy the end time by 1 billion)
and final amount is 25% of original or 0.25P
0.25P=P(1/2)^(t/1.3)
divide both sides by P
0.25=(1/2)^(t/1.3)
take ln of bot sides
ln(0.25)=ln((1/2)^(t/1.3))
property of logarithms
ln(0.25)=(t/1.3)ln(1/2)
divide both sides by ln(1/2)
(ln(0.25))/(ln(1/2))=t/1.3
times both sides by 1.3
(1.3ln(0.25))/(ln(1/2))=t
remember that this is billion so
(1,300,000,000ln(0.25))/(ln(1/2))=t
2600000000.0001=t
about 2.6 billion years
Answer:
Explanation:
In the first minute the elevator desends 4 meters. The elevator stops at minute two. In minute three the elevator decends another 4 meters. The elevator stops at minute four. In minute five the elevator decends two meters.
Epigeal germination is a botanical term indicating that the germination of a plant takes place above the ground. An example of a plant with epigeal germination is the common bean (Phaseolus vulgaris). The opposite of epigeal is hypogeal (underground germination).
The appropriate answer is d. Dead plants in a swampy environment is the perfect environment for the beginning of the coal forming process. Over time layers pile up in this anaerobic environment. The plant or organic material gets buried overtime by dirt or rocks. Millions of years of burial will expose the matter to heat and pressure and will eventually lead to the formation of coal and other petroleum products.
