Question

Question 1(Multiple Choice Worth 5 points) (07.01 MC) The amount of radioactive uranium changes with time. The table below shows the amount of radioactive uranium f(t) left after time t: t(hours) 0 0.5 1 f(t) 100 50 25 Which exponential function best represents the relationship between f(t) and t?

Answer 1

This represents a half life equation - since as time increases, radioactivity decreases by half. If we take our exponential function

y = a(r)^t, r = 1/2 since as t increases, y halves. The initial amount of radiation is 100, so a = 100

Thus we get f(t) = 100(1/2)^t

Answer 2

the answer would be f(t) = 100(0.25)t