Question

The amount in kilograms, a, of s radioactive element that remains after t hours can be modeled by the equation a=0.65(0.92)t. What is the rate of decrease of this radioactive element?A- 35% per hourB- 92% per hourC- 8% per hour D- 65% per hour

Answer 1

C)8% per hour

1) In this question, the key to solving this question is the factor of decay.

2) Let's rewrite it step by step so that it is clear enough to answer the question:

`\begin{gathered} a=0.65\left(1-0.08\right)^t \\ a=0.65\left(0.92\right)^t \end{gathered}`

As we can see, in this question there is a decay of 0.08 ( 8% per hour)