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- .MCD 20000 0
- .CMD PLOTFORMAT logs=0,0 subdivs=1,1 size=5,15 type=l
- .CMD FORMAT rd=d ct=10 im=i et=3 zt=15 pr=3 mass length time charge
- .CMD SET ORIGIN 0
- .CMD SET TOL 0.001000
- .CMD MARGIN 0
- .CMD LINELENGTH 78
- .CMD SET PRNCOLWIDTH 8
- .CMD SET PRNPRECISION 4
- .CMD FILENAME data1 data1
- .CMD FILENAME data2 data2
- .TXT 1 0 1 20
- a1,19,17,18
- RADIOACTIVE DECAY
- .TXT 2 9 4 55
- a4,55,53,162
- This document shows the results of radioactive decay.
- Element A decays with a half-life of thalfA into
- element B. Element B decays with a half-life of
- thalfB.
- .EQN 5 1 1 9
- gm~1M
- .EQN 0 20 1 9
- yr~1T
- .TXT 2 -30 1 22
- a1,21,19,20
- Initial conditions:
- .TXT 2 9 1 30
- a1,30,28,29
- Initial amount of element A:
- .EQN 0 41 1 14
- A0:100*gm
- .TXT 2 -41 1 13
- a1,13,11,12
- Half-lives:
- .EQN 0 41 1 17
- thalfA:10*yr
- .EQN 1 0 1 18
- thalfB:100*yr
- .TXT 2 -41 2 31
- a2,31,29,44
- Ratio: mass of 1 atom of A to
- 1 atom of B:
- .EQN 1 41 1 10
- α:1.1
- .TXT 2 -50 1 27
- a1,26,24,25
- Compute decay constants:
- .EQN 2 10 3 14
- kA:ln(2)/thalfA
- .EQN 0 40 3 14
- kB:ln(2)/thalfB
- .TXT 4 -50 1 19
- a1,18,16,17
- Decay functions:
- .EQN 2 10 2 21
- A(t):A0*e^-(kA*t)
- .EQN 3 0 2 39
- B(t):-α*A0*e^-(kB*t)*(e^-(kA*t)-1)
- .TXT 4 -10 1 39
- a1,38,36,37
- Graph the mass of A and B over time:
- .EQN 2 10 1 25
- t:0*yr,2*yr;200*yr
- .EQN 0 35 1 27
- t2:0*yr,10*yr;200*yr
- .EQN 2 -45 16 42
- A0&0*gm&A(t),B(t){1,1,15,30,l}@200*yr&0*yr&t
- .EQN 0 46 24 7
- t2/yr=
- .EQN 0 10 24 8
- A(t2)/gm{19137}=
- .EQN 0 10 24 8
- B(t2)/gm{18993}=
- .TXT 10 -24 1 3
- a1,3,1,2
- B
- .TXT 4 0 1 3
- a1,3,1,2
- A
-