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(I pont) The half life of substance A is 19 years, and substance B decays at a r

ID: 3064872 • Letter: #

Question

(I pont) The half life of substance A is 19 years, and substance B decays at a rate of 30 % each doade (a) Find a formula for a function f) that gives the amount of substance A, in milligrams, left after f years, given that the initial quantity was 100 miligrams help (formulas) (a) Find a formula for a function g() that gives the amount of substance 8, in miligrams, left after f years, given that the initial quantity was 100 miligrams g) 100(1-70 help (formulas) (c) Of which substance is there less in the long term? A. There is less of substance A in the long term B. There is less of substance B in the long term C. There is no way to tell.

Explanation / Answer

a)
f(t) = A e^(-bt)
A = 100
b = ln 2 / t_0.5
= (ln 2) /19
f(t) = 100 e^(-0.0364814 t)
b)
similarly
here b =- (ln (1 - 0.3))/10
= 0.035667
hence
g(t) = 100 e^(-0.035667 t)

c)
since 0.03648 > 0.035667
decay rate of A is more that that of B
there is less of substance A in the long term