Assume the half-life of the substance is 34 days and the initial amount is 116 grams.
Whats the formula in terms of t? A=?
How long would it talk to decay to 2.3 grams.
Thanks
2007-02-05 13:26:29 · 3 answers · asked by J R 2 in Science & Mathematics ➔ Mathematics
ok:
the formula in terms of t is:
A(amount) = 116(1/2) ^ (t/34) where t is in days
as you can see, t/34 means that for every 34 days, you will multiply by 1/2.
thus, to find out how long it would take to get to 2.3 grams, just set A= 2.3 and solve for t.
(*it would take 193 days ( you get 192.3158 but you have to round up to the next day))
2007-02-05 13:30:21 · answer #1 · answered by Ace 4 · 0⤊ 0⤋
The equation is:
t= [log (Ae/Ao)]/log 0.5 *t1/2
Where:
Ao= original amount of substance; (116g)
Ae= amount of substance remaining; (116g-2.3g= 113.7g)
t1/2= half life; (34 days)
Substituting in:
t= [log(113.7/116)]/log0.5 *34
t= -0.008698/-0.301030 *34
t=0.98 days
2007-02-05 13:29:13 · answer #2 · answered by sciencewiz 4 · 0⤊ 0⤋
Pay attention in class.
I hate logs.
Good luck.
2007-02-05 13:29:38 · answer #3 · answered by Anonymous · 0⤊ 0⤋