Can Someone help me with this?
Last edited by mr fantastic; Oct 31st 2010 at 04:20 PM.
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Originally Posted by lilwayne Can Someone help me with this? If the half life is 3.3 days and you have m = 880 mg at t = 0 then you will obviously have 440 mg when t = 3.3 ....
Originally Posted by mr fantastic If the half life is 3.3 days and you have m = 880 mg at t = 0 then you will obviously have 440 mg when t = 3.3 .... yeah i know that but i dont get what to fill in the blanks..
$\displaystyle 440 = 880e^{3.3k}$ solve for $\displaystyle k$ and finish the problem.
Originally Posted by skeeter $\displaystyle 440 = 880e^{3.3k}$ solve for $\displaystyle k$ and finish the problem. yeah i ended up doing that and what i got was 1/2 and 3.3 for the first 2 blanks. 2 and 3.3 for the second 2 blanks. 880, 2 and 3.3 for the last 3 blanks. but it was wrong, what did i do wrong?
Originally Posted by lilwayne yeah i ended up doing that and what i got was 1/2 and 3.3 for the first 2 blanks. 2 and 3.3 for the second 2 blanks. 880, 2 and 3.3 for the last 3 blanks. but it was wrong, what did i do wrong? you forgot to divide the right side by 880 ... $\displaystyle 440 = 880e^{3.3k}$ divide both sides by 880 ... $\displaystyle \displaystyle \frac{1}{2} = e^{3.3k} $ continue ...
yeah i did that, then i did ln1/2 = lne^3.3k which is ln1/2 = 3.3k and i was told that ln(1/2) = -ln(2) so i had k = -ln(2)/3.3 is that right so far?
Nvm got it.
Originally Posted by lilwayne Nvm got it. you're welcome.