Exponential Function Solving - Decay (Continuous, Mis-matched Time Units) - Scenario to Time

Level 1

The topics in this unit focus on mastering exponential growth and decay functions. Work on practice problems directly here, or download the printable pdf worksheet to practice offline.

Exponential Function Solving - Decay (Continuous, Mis-matched Time Units) - Scenario to Time Worksheet

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Exponential Function Solving - Decay (Continuous, Mis-matched Time Un...
1
A radioactive material starts at an isotope concentration of 200ppm. It decays continuously at 3% per hour. After a certain number of days it has decayed to an isotope concentration of 152ppm.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -1 over 24 times r over \ln{\frac{R {R sub 0 }}}
b A LaTex expression showing t = -1 over 24 times \ln{\frac{R over R sub 0 }}{r}
c A LaTex expression showing t = -24 times \ln{\frac{R over R sub 0 }}{r}
d A LaTex expression showing t = -24 times \frac{\ln{R times R sub 0 }}{r}
2
A bird population starts at 600. It declines continuously at 4% per year. After a certain number of quarters it has decreased to a population of 491.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -4 times \ln{\frac{P over P sub 0 }}{r}
b A LaTex expression showing t = -4 times r over \ln{\frac{P {P sub 0 }}}
c A LaTex expression showing t = -1 over 4 times \ln{\frac{P over P sub 0 }}{r}
3
A bird population starts at 200. It declines continuously at 3% per quarter. After a certain number of years it has decreased to a population of 152.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -1 over 4 times r over \ln{\frac{P {P sub 0 }}}
b A LaTex expression showing t = -1 over 4 times \ln{\frac{P over P sub 0 }}{r}
c A LaTex expression showing t = -4 times \frac{\ln{P times P sub 0 }}{r}
4
A bird population starts at 400. It declines continuously at 3% per quarter. After a certain number of years it has decreased to a population of 324.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -4 times \frac{\ln{P times P sub 0 }}{r}
b A LaTex expression showing t = -4 times \ln{\frac{P over P sub 0 }}{r}
c A LaTex expression showing t = -1 over 4 times \ln{\frac{P over P sub 0 }}{r}
d A LaTex expression showing t = -1 over 4 times r over \ln{\frac{P {P sub 0 }}}
5
A radioactive material starts at an isotope concentration of 400ppm. It decays continuously at 2% per week. After a certain number of days it has decayed to an isotope concentration of 340ppm.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{R over R sub 0 }}{r}
b A LaTex expression showing t = -1 over 7 times \ln{\frac{R over R sub 0 }}{r}
c A LaTex expression showing t = -7 times r over \ln{\frac{R {R sub 0 }}}
6
A radioactive material starts at an isotope concentration of 700ppm. It decays continuously at 3% per day. After a certain number of weeks it has decayed to an isotope concentration of 602ppm.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{R over R sub 0 }}{r}
b A LaTex expression showing t = -7 times \frac{\ln{R times R sub 0 }}{r}
c A LaTex expression showing t = -1 over 7 times \ln{\frac{R over R sub 0 }}{r}
7
A whale population starts at 200. It declines continuously at 6% per quarter. After a certain number of years it has decreased to a population of 131 whales.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -4 times \ln{\frac{P over P sub 0 }}{r}
b A LaTex expression showing t = -1 over 4 times r over \ln{\frac{P {P sub 0 }}}
c A LaTex expression showing t = -1 over 4 times \ln{\frac{P over P sub 0 }}{r}
8
A radioactive material starts at an isotope concentration of 500ppm. It decays continuously at 8% per day. After a certain number of weeks it has decayed to an isotope concentration of 285ppm.
How would you solve for the time given this scenario?
a A LaTex expression showing t = -1 over 7 times \ln{\frac{R over R sub 0 }}{r}
b A LaTex expression showing t = -7 times \frac{\ln{R times R sub 0 }}{r}
c A LaTex expression showing t = -1 over 7 times r over \ln{\frac{R {R sub 0 }}}
d A LaTex expression showing t = -7 times \ln{\frac{R over R sub 0 }}{r}