A 120-g sample of a radioactive isotope loses mass at a rate proportional to the…

MATHEMATICS · Subjective · AP · Calculus AB · Differential Equations · Differential Equations

Problem

A 120-g sample of a radioactive isotope loses mass at a rate proportional to the amount present. Using

m

for mass (in grams) and

t

for time (in days), write the differential equation that relates

\dfrac{dm}{dt}

m

, showing the appropriate sign of the constant of proportionality.