This question assesses the student's ability to solve exponential growth equations using natural logarithms and determine specific values such as doubling time.
The population grows according to P(t)=1000e0.05t. Determine the doubling time.
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Question 2
Skill question
Calculate the amount at t=2 for the model A(t)=12e0.8t+3.
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Question 3
Skill question
Find the initial amount of bacteria in the model A(t)=5e−3t+9.
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Question 4
Skill question
Exponential functions and decay, logarithms, and significant figures.
A drug concentration decays as C(t)=5e−0.1t mg/L. Find its half-life.
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Question 5
Skill question
A hot object cools as T(t)=20+80e−0.3t. Find the time when T(t)=50∘C.
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Question 6
Skill question
For C(t)=10e−0.5t+2, how long until C(t) is within 0.5 of its long-term value?
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Question 7
Skill question
In the model A(t)=500e−0.2t+50, find the time t when A(t)=100.
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Question 8
Skill question
For the model P(t)=100e−t+20, determine t→∞limP(t).
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Question 9
Skill question
Radioactive decay is modeled by N(t)=100e−0.693t/5. Find the time when N(t)=25.
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Question 10
Skill question
Given A(t)=50e−0.2t+10, find the time t when A(t)=30.
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Question 11
Skill question
In the model P(t)=200e0.1t+50, find the time t when P(t)=350.