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 12:49:06 · 3 answers · asked by J R 2 in Science & Mathematics ➔ Mathematics
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 13:28:04 · answer #1 · answered by sciencewiz 4 · 0⤊ 0⤋
The formula is 116*2^(-t/34)
At t = 0 this is 116 : check
At t = 34 this is 116*2^(-1) = 1/2*116 : check
At t = 68 this is 116*2^(-2) = 1/4*116 : check
So use logs to solve 116*2^(-t/34) = 2.3
2007-02-05 13:26:35 · answer #2 · answered by sofarsogood 5 · 0⤊ 0⤋
sorry i tried i couldn't do it.
2007-02-05 12:53:53 · answer #3 · answered by BeBop 3 · 0⤊ 1⤋