Posted by **Emily** on Thursday, December 10, 2009 at 7:20pm.

31. Radioactive decay of material is determined using the formula N = Noe^-kt. Find the constant k for Plutonium-239 given that its half-life is 24,390 years.

==> I don't really get where to start here because the problem does not give you how much Plutonium-239 there is. I just need a hint, no need to work out the entire problem for me please :)

35. The exponential growth rate of the population of Europe west of Russia is 1% per year. What is the doubling time?

==> I just used the rule of 72 to estimate it out to be about 72 years, but I don't think this is the correct process. Can anyone help me on these? Thanks so much!! :)

## Answer This Question

## Related Questions

- Math - _The_Natural_Base_e_ An accident in 1986 at the Chernobyl nuculear plant ...
- science - suppose you have 100grams of radioactive plutonium-239 with a half-...
- Calculus - The rate of decay is proportional to the mass for radioactive ...
- CHEMISTRY - Suppose you had a detection device that could count every decay ...
- Math - D.E.Q. - The half-life of a radioactive isotope is the amount of time it ...
- Physics - Suppose you have 100 g of radioactive plutonium-239 with a half-life ...
- Physics - Suppose you have 100 g of radioactive plutonium-239 with a half-life ...
- Math - A radioactive substance decays according to the formula Q(t) = Q0e−...
- Math - A radioactive substance decays according to the formula Q(t) = Q0e−...
- calculus - Question: "Plutonium isotope Pu-239 has a half-life of 24,100 years. ...

More Related Questions