Workshop:  HalfLife

STUDENT #1 NAME:                                                                

STUDENT #2 NAME:

Consider the following radioactive decay data:

({{  time-min ,   0.5 ,  1.0  ,  1.5  ,  2.0  ,  2.5  ,  3.0  , 3.5  ,  4.0  }, {  R[
                t] c.p.s. ,  3.9  ,  3.0  ,   2.4 ,  1.8  ,  1.4  ,  1.1  ,   0.87 ,   0.68 }})

Use Mathematica to interpret the above data for the problems below.  Show all your work.  Finish your work by the end of class today, September 20. 2052.

Problem #1:  Graph the counts per second, R[t] versus the elapsed time t (measured in minutes).  Collect the data together in a list using the Table function.  Give your data list a name and use the ListPlot function to do the graphing.

Problem #2:  Calculate the natural Logarithm Log[R] and graph Log[R] versus the elapsed time.  Calculate the slope of your graph using pairs of points on your graph (and average the results).

Problem #3:  Calculate the numerical value for the decay constant λ, the decay time τ, and the half-life.

Problem #4:  Do a least square fit of the Log[R] versus time data and get a best straight line.  How well does your slope agree with the answer you got in problem #2?