In a science experiment a substance is decaying exponentially. Its mass, M grams, at time t minutes is given by M= 300e^-0. 5t
The initial mass is found by putting t=0 into the given equation, so the initial mass is 300g. When the mass has decreased to half its value, M=150g. This gives us 150=300e^-0.05t, so e^-0.05t=1/2. Natural log of both sides and re-arranging for t gives t=-ln(1/2)/0.05=13.9 minutes.
TT
Related Maths A Level answers
All answers ▸How do you solve a Differential equation using integrating factors?
A cuboid has a rectangular cross section where the length of the rectangle is equal to twice its width x cm. THe volume is 81 cm^3. a) show that the total length L cm of the cuboid is given by L=12x+162/x^2
Using the sum, chain and product rules, differentiate the function f(x) = x^n +x^3 * sin(1/[3x])
Solve Inx + In3 = In6