The mass of a substance is increasing exponentially. Initially its mass is 37.5g, 5 months later its mass is 52g. What is its mass 9 months after the initial value to 2 d.p?
M=37.5ekt 52=37.5ek5 52/37.5=e5k ln(52/37.5)=5k (1/5)(ln(52/37.5))=k k≈0.06538 when t=9, M=37.5e9*0.06538 M=67.54