Question
200 mg of a radioactive substance decays at a rate of 5% per day.
A) Write an equation that models the mass (M) as a function of t (time in days).
M(t)=______
B) What will be the mass of the substance after 10 days?
C) How long will it take for the radioactive substance to decay to 5rg?
A) Write an equation that models the mass (M) as a function of t (time in days).
M(t)=______
B) What will be the mass of the substance after 10 days?
C) How long will it take for the radioactive substance to decay to 5rg?
Answers
mathhelper
M(t) = 200 (.95)^t, where t is the number of days
B) when t = 10
M(10) = 200(.95)^10 = .....
c) when is M(t) = 5 ???
200(.95)^t = 5
.95^t = .025
t log .95 = log .025
t = log .025/log .95 = .....
B) when t = 10
M(10) = 200(.95)^10 = .....
c) when is M(t) = 5 ???
200(.95)^t = 5
.95^t = .025
t log .95 = log .025
t = log .025/log .95 = .....