A radioactive substance decays according to the following function, where yo is the initial amount present, and y is the amount present at time t (in days). y=y_o e^-0.0645t Find the half-life of this substance. Do not round any intermediate computations, and round your answer to the nearest tenth days

Answer :

Answer:

Therefore 10.75 days is the half life of the given radioactive substance.

Step-by-step explanation:

Given that, a radioactive substance decays function is

[tex]y=y_0 \ e^{-0.0645t}[/tex]

where y₀= initial amount of radioactive substance

y= The amount of radioactive substance at time t.

t is in days

Half life is the time required to reduce the amount of the substance to its half of the initial amount.

For half life

[tex]y=\frac{1}{2} y_0[/tex]

Putting the value of y in the given function

[tex]\frac12y_0=y_0 \ e^{-0.0645t}[/tex]

[tex]\Rightarrow \frac12= \ e^{-0.0645t}[/tex]

Taking ln both sides

[tex]\Rightarrow ln( \frac12)= ln(e^{-0.0645t})[/tex]

[tex]\Rightarrow ln1-ln2=-0.0645t[/tex]     [ [tex]\because lne^a=a,[/tex][tex]ln(\frac ab)= ln \ a- ln \ b[/tex]  ]

[tex]\Rightarrow-ln2=-0.0645t[/tex]

[tex]\Rightarrow t=\frac{-ln2}{-0.0645}[/tex]

      =10.75 days.

Therefore 10.75 days is the half life of the given radioactive substance.

xero099

The half-life of the substance is approximately 10.7 days.

The decay of a radioactive isotope is represented by the following exponential model:

[tex]y = y_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (1)

Where:

  • [tex]y_{o}[/tex] - Initial amount.
  • [tex]y[/tex] - Current amount.
  • [tex]t[/tex] - Time, in days.
  • [tex]\tau[/tex] - Time constant, in days.

The half-life of the substance ([tex]t_{1/2}[/tex]) can be found by this expression:

[tex]t_{1/2} = \tau \cdot \ln 2[/tex] (2)

If we know that [tex]\tau = 15.504[/tex], then the half-life of this substance is:

[tex]t_{1/2} = 15.504\cdot \ln 2[/tex]

[tex]t_{1/2} \approx 10.7[/tex]

The half-life of the substance is approximately 10.7 days.

We kindly invite to check this question on half-life: https://brainly.com/question/16387602

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