math

posted by manisha

The rate of increase of bacteria in a culture is proportional to the number of bacteria present .if the original number of bacteria double in the two hours, in how many hours will it be five times?

  1. Steve

    this is exponential growth. Since it doubles in 2 hours, the population is after t hours is

    p(t) = A*2^(t/2)

    So, it will be 5 times as big as at first when

    2^(t/2) = 5

    or, you can start from scratch, using

    dp/dt = kp
    dp/p = k dt
    lnp = kt+lnA
    p = A*e^(kt)
    and work it from there

Respond to this Question

First Name

Your Answer

Similar Questions

  1. Precalculus

    NEED HELP ASAP PLEASE!! A bacteria culture starts with 2000 bacteria and the population doubles every 3 hours. a) A function that models the number of bacteria after t hours is p(t)=____________?
  2. pre calculus

    if there are initial 2500 bacteria in a culture, and the number of bacteria double each hour, the number of bacteria after t hours cab n be found using the formula=N=2500(2^t).how long will it take the culture to grow to 75,000 bacteria.
  3. MATH :)

    3. In Biology, it is found that the bacteria in a certain culture double every half-hour. If the initial number of bacteria in culture is 1000, A. Find the defining equation for the number N of bacteria in culture after T hours, assuming …
  4. Algebra 2

    If there are initially 1500 bacteria in a culture, and the number of bacteria double each hour, the number of bacteria after t hours can be found using the formula N=1500(2^t). How many bacteria will present after 7 hours?
  5. calculus

    2. The rate of change in the number of bacteria in a culture is proportional to the number present. In a certain laboratory experiment, a culture has 10,000 bacterial initially, 20,000 bacteria at time t1 minutes, and 100,000 bacteria …
  6. math

    The number of bacteria in a culture is modeled by n(t)=1710e071t (a) The initial number of bacteria is (b) The relative rate of growth of this bacterium population is (c) The number of bacteria after 3 hours is (d) After how many hours …
  7. Math

    he number of bacteria in a culture is modeled by n(t)=1710e071t (a) The initial number of bacteria is (b) The relative rate of growth of this bacterium population is (c) The number of bacteria after 3 hours is (d) After how many hours …
  8. math

    The number of bacteria in a culture is modeled by: n(t) = 1330e^(0.42t) (a) The initial number of bacteria is: (b) The relative rate of growth of this bacterium population is: (c) The number of bacteria after 3 hours is: (d) After …
  9. College Algebra

    The number of bacteria in a certain culture increased from 500 to 1000 between 7:00 A.M. and 9:00 A.M. Assuming growth is exponential, the number f(t) of bacteria t hours after 7:00 A.M. is given by f(t) = 500(2)^t/2. (a) Estimate …
  10. pre calc

    The number N of bacteria in a culture at time t (in hours) grows exponentially according to the function N(t) = 1000e^0.01t. 1.What is the population after 4 hours?

More Similar Questions