Understanding exponential growth and decay models:

Cards (63)

  • What is the formula for exponential growth?
    y=y =Ce(kt) Ce^(kt)
  • What does the variable `y` represent in the exponential growth formula?
    Quantity at time `t`
  • In exponential decay, the decay constant `k` must be positive.
    True
  • The formula for exponential growth remains the same regardless of the quantity being modeled.
    True
  • What is the formula for exponential decay?
    y=y =Ce(kt) Ce^( - kt)
  • In the exponential decay formula, `k` is called the decay constant
  • The differential equation for exponential growth is `dy/dt = ky`.

    True
  • Match the differential equation with its model:
    dy/dt=dy / dt =ky ky ↔️ Growth
    dy/dt=dy / dt =ky - ky ↔️ Decay
  • In the decay model `dy/dt = -ky`, the constant `k` is positive.

    True
  • Steps to calculate the growth/decay rate `k` for an exponential model:
    1️⃣ Identify initial quantity `C` and final quantity `y` at time `t`
    2️⃣ Use the formula for growth or decay to find `k`
  • What is the growth rate of a bacteria population that grows from 500 to 1200 in 3 hours?
    0.29
  • What is the decay rate of a substance that reduces from 300 grams to 150 grams in 8 days?
    0.087
  • What does the growth constant `k` represent in exponential growth?
    Rate of increase
  • What is the formula for exponential decay?
    y = Ce^(-kt)
  • What is the formula for a radioactive substance decaying at 5% per year if its initial mass is 100 grams?
    y = 100e^(-0.05t)
  • The formula to find `k` for exponential decay is `k = (ln(y/C)) / t`.
    False
  • A bacteria population grows from 500 to 1200 in 3 hours. What is the growth rate `k`?
    0.29
  • The formula for exponential decay is `k = (ln(y/C)) / t`
    False
  • What is the general solution for the differential equation `dy/dt = ky` in exponential growth?
    y=y =Cekt Ce^{kt}
  • What is the solution to the differential equation `dy/dt = -ky` for exponential decay?
    y=y =Cekt Ce^{ - kt}
  • Suppose a population starts at 100 cells and grows at 20% per hour. What is the expression for `y` at time `t`?
    y=y =100e0.2t 100e^{0.2t}
  • What is the formula used to model population growth?
    P(t)=P(t) =P0ekt P_{0}e^{kt}
  • In the exponential growth formula, `C` represents the initial quantity
  • In the exponential growth formula, `t` represents the time elapsed
  • What does the variable `C` represent in the exponential decay formula?
    Initial quantity
  • What does the variable `y` represent in the exponential growth formula?
    Quantity at time `t`
  • The decay constant `k` in exponential decay must be positive.

    True
  • What does the variable `y` represent in the exponential decay formula?
    Quantity at time `t`
  • The differential equation for exponential decay is `dy/dt = -ky
  • What do the differential equations for exponential growth and decay express?
    Rate of change
  • What is the differential equation for a population growing at 2% per year if it starts at 1000?
    dy/dt = 0.02y
  • For exponential growth, the formula to find `k` is `k = (ln(y/C)) / t
  • The growth/decay rate is a percentage per unit time
  • Exponential growth occurs when a quantity increases at a constant rate.
    False
  • A bacteria population doubles every hour. What is the growth constant `k` for this scenario?
    ln(2)
  • In the exponential decay formula `y = Ce^(-kt)`, the variable `C` represents the initial quantity
  • Match the differential equation with its description:
    `dy/dt = ky` ↔️ Growth
    `dy/dt = -ky` ↔️ Decay
  • What formula is used to calculate the growth rate `k` if `y = Ce^(kt)`?
    k = (ln(y/C)) / t
  • What is the differential equation for a population growing at 2% per year from an initial size of 1000?
    dydt=\frac{dy}{dt} =0.02y 0.02y
  • What does `y` represent in the growth/decay rate formulas?
    Final quantity