Maths

posted by .

A(t)=A'e^(-t/r)
where A(t) is the amount after time t, A' is the initial amount at t=0 and r is the decay time.

Give an interpretation of the parameter r.

• Maths -

r is the length of time required for the amount of A to decrease by a factor of 1/e

Similar Questions

1. compound interest

How do I solve these problems? Complete the table for a savings account in which interest is compounded continuously. 1. Initial Investment: \$1000 Annual % Rate: 3.5% Time to Double: ?
2. Physics

A first order exponential decay can be written as A(t)= Ae^(-t/r) where A(t) is the amount (of substance) after time t, A is the initial amount at time t=0 and r is the decay time. The fall time is defined as the time in which A(t) …
3. calculus

Carbon-14 is a radioactive substance produced in the Earth's atmosphere and then absorbed by plants and animals on the surface of the earth. It has a half-life (the time it takes for half the amount of a sample to decay) of approximately …
4. Math - D.E.Q.

The half-life of a radioactive isotope is the amount of time it takes for a quantity of radioactive material to decay to one-half of its original amount. i) The half-life of Carbon 14 (C-14) is 5230 years. Determine the decay-rate …
5. Differential Equations

Model radioactive decay using the notation t = time (independent variable) r(t) = amount of particular radioactive isotope present at time t (dependent variable) -λ = decay rate (parameter) Note that the minus sign is used so …
6. Calculus

The radioactive element polonium decays according to the law given below where Q0 is the initial amount and the time t is measured in days. Q(t) = Q0 ยท 2-(t/140) If the amount of polonium left after 700 days is 45 mg, what was the …
7. Math

The initial amount of sugar in fermenting a batch of beer is 5.5grams. Over time the sugar decreases at a rate of 0.1grams per day. a. what is the amount of sugar that remains after 7 days?
8. Math!

The initial amount of sugar in fermenting a batch of beer is 5.5 grams. Over time the sugar decreases at a rate of 0.1grams per day. a.What is the amount of sugar that remains after 7 days?
9. Pre-calculus

Complete the table assuming continuously compounded interest. (Round your answers to two decimal places.) Initial Investment: Annual % Rate: Time to Double: 8 yr Amount After 10 Years: \$1700 I don't understand how to get in the initial …
10. Exponential Growth and Decay

Can somebody please check my answers? 1. Identify the initial amount a and the growth factor b in the exponential function. g(x)=14*2^x a)a=14, b=x b)a=14, b=2 <<<< c)a=28, b=1 d)a=28, b=x 2. Identify the initial amount

More Similar Questions