Save
...
Unit 7: Differential Equations
7.7 Exponential Models with Differential Equations
Understanding exponential growth and decay models:
Save
Share
Learn
Content
Leaderboard
Share
Learn
Cards (47)
What is exponential growth characterized by?
Proportional increase to current value
What is exponential decay characterized by?
Proportional decrease to current value
What is the condition for exponential growth in the general formula?
k > 0
What happens to the quantity P over time in exponential decay?
Decreases exponentially
What is the behavior of exponential decay over time?
Decreases at a decelerating rate
Match the decay type with its general form and behavior over time:
Exponential ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
−
k
P
- kP
−
k
P
, Decreases at a decelerating rate
Linear ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
−
k
- k
−
k
, Decreases at a constant rate
The rate constant k is negative for
exponential decay
.
True
In exponential decay, the decay rate constant k is always positive.
False
What does the variable 'k' represent in exponential decay?
Decay rate constant
Exponential decay slows down as the
quantity
decreases.
True
The rate constant in the exponential formula determines how fast a quantity changes over
time
.
The growth/decay rate 'k' is found by taking the natural logarithm of the
change ratio
and dividing by the time interval.
True
What type of growth is characterized by an accelerating increase over time?
Exponential growth
What is the decay rate constant 'k' called in exponential decay?
Decay rate constant
What does the decay rate constant 'k' determine in exponential decay?
Rate of decrease
What is the general form of the exponential decay equation?
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
−
k
P
- kP
−
k
P
In exponential decay, the rate of
decrease
slows down as the quantity decreases.
True
What is the general formula for exponential growth and decay?
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
P
kP
k
P
Match the characteristic with the type of exponential model:
Growth rate increases exponentially ↔️ Exponential growth
Rate constant is negative ↔️ Exponential decay
What are the initial and final quantities denoted as in the calculation of 'k'?
P
0
P_{0}
P
0
and
P
t
P_{t}
P
t
The rate constant 'k' is negative in exponential growth models.
False
The growth rate constant in exponential growth determines the rate of growth.
True
Match the growth type with its general form and behavior over time:
Exponential ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
P
kP
k
P
, Increases at an accelerating rate
Linear ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
k
k
, Increases at a constant rate
The decay rate constant in
exponential decay
determines the rate of decrease.
True
Match the growth type with its general form and behavior over time:
Exponential ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
P
kP
k
P
, Increases at an accelerating rate
Linear ↔️
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
k
k
, Increases at a constant rate
In exponential decay, the rate of decrease
decelerates
over time.
What is the general formula for exponential growth and decay?
d
P
d
t
=
\frac{dP}{dt} =
d
t
d
P
=
k
P
kP
k
P
What does a positive value of 'k' indicate in exponential models?
Exponential growth
If a population starts at 100 and grows to 150 in 5 years, what is the growth rate 'k'?
k
≈
0.081
k \approx 0.081
k
≈
0.081
Exponential decay
is a model where a quantity decreases at a rate proportional to its current
value
.
In linear decay, the
quantity
decreases by a fixed amount per unit time.
True
Exponential decay is a model where a quantity decreases at a rate proportional to its current
value
In linear decay, the quantity decreases at a constant
rate
Exponential decay occurs when the rate constant 'k' is positive.
False
A negative value of the growth/decay rate
k
k
k
indicates exponential decay
Order the steps involved in calculating the growth/decay rate 'k'.
1️⃣ Identify the initial and final quantities
2️⃣ Calculate the change ratio
3️⃣ Determine the time interval
4️⃣ Compute the rate 'k' using the formula
In linear decay, the
quantity
decreases by a fixed amount per unit time.
True
Steps to calculate the growth/decay rate 'k':
1️⃣ Identify the initial and final quantities (`P_0` and `P_t`).
2️⃣ Calculate the change ratio:
P
t
P
0
\frac{P_{t}}{P_{0}}
P
0
P
t
.
3️⃣ Determine the time interval (`t`).
4️⃣ Compute 'k' using the formula:
k
=
k =
k
=
ln
(
P
t
P
0
)
t
\frac{\ln(\frac{P_{t}}{P_{0}})}{t}
t
l
n
(
P
0
P
t
)
.
What does a negative value of 'k' indicate in exponential models?
Exponential decay
Exponential growth
is a model where a quantity increases at a rate proportional to its current
value
.
See all 47 cards