# Math

the concentration of a certain substance in our organism is given by the model Q9t) = Q(subscript 0) e^-0.1960t

a) what quantity of substance is present in the organism of this individual 3 hours after ingestion?

b) after how many hours will there only be 10% of this substance ingested by the individual?

1. 👍
2. 👎
3. 👁
1. Q(t) = Q0 e^-0.1960t
where t=elapsed time in hours (Check, not mentioned in the question).
So after three hours,
Q(3) = Q0 e^(-0.1960*3)=?

Q(t) = 0.9Q0
or
e^(-0.1960t)=0.9
Take natural log:
-0.1960t = ln(0.9)
t=ln(0.9)/(-0.1960)=?

I'll leave it to you to work on your calculator.

1. 👍
2. 👎

## Similar Questions

1. ### Science

Ethan is observing chemical and physical properties of a substance. He heats a substance and observes that the substance turns from a brown solid to a black powder. He refers to several chemistry journals that claim this

2. ### Science

A scientist discovered a microscopic, unicellular organism with no nucleus. Which of the following correctly describes the organism? A.The organism is a plant. B.The organism is an animal. C.The organism is a prokaryote.** D.The

3. ### Math help

In which type of symbiotic relationship is one organism helped while another organism is neither benefitted nor harmed? A: Mutualism B: Predation C: Commensalism D: Parasitism

4. ### 11Science

A diploid organism has five pairs of chromosomes in each somatic cell. Assuming that no crossing over occurs, how many genetically distinct gametes can this organism produce?

1. ### Bio

What is an advantage of using an organism's scientific name rather then its common name? A.The scientific name is always given in the native language B.The scientific name is based upon the organism's kingdom and phylum C.The

If the proteins making up a gene were changed or mutated, what impact would this likely have on an organism?(1 point) A trait of the organism may be changed only in a positive way. There would be no change as the proteins do not

3. ### science

Imagine you have two beakers. Both beakers are filled with the same amount of water. The water in both beakers is the same temperature as well. You add 50 g of Substance A to the first beaker, and 50 g of Substance B to the second

4. ### algebra

A radioactive substance decays according to the formula A=A0e^kt where A0 is the initial amount of substance (in grams) A is the amount of substance(in grams) after t years k is a constant The half-life of the substance is 10

1. ### biology

What environmental conditions would favor sexual reproduction? What environmental conditions would favor asexual reproduction? Organism - sexual reproduction - gonads asexual reproduction - honeybees - Is pillbugs an asexually

2. ### Science

1.) when might preserved remains of an entire organism form? A.) when sediment buries the hard part of an organism B.) when an event such as a quick burial or freezing preserves an entire organism ******* C.) when minerals replace

3. ### Science-plz help

which of the following show the correct order from smallest to largest a- community - organism - population-ecosystem b- organism -population- community -organism c- population-ecosystem- community-organism d- organism

4. ### Biology

Examine the amino acid sequences from three organisms (A,B and C). Which two organisms are the most closely related? Organism A: Val-Ser-Thr-Val Organism B-Ala-Leu-Ala Organism C: Val-SerAsp-Met point) A and B They are all equally