SOLUTION: y=70(e^(0.19t)), where t is in hours. use natural logarithms to find the half life of this element

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Question 882716: y=70(e^(0.19t)), where t is in hours. use natural logarithms to find the half life of this element
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
You start with 70.
When will it be 35?
You need a negative exponent or else the amount of material increases.
35=70e%5E%28-0.19t%29
1%2F2=e%5E%28-0.19t%29
-0.19t=ln%281%2F2%29
t=ln%281%2F2%29%2F%28-0.19%29
t=3.64 hours