T.A. MARRYSHOW COMMUNITY COLLEGE
SCHOOL OF ARTS, SCIENCES AND PROFESSIONAL STUDIES
DEPARMENT OF NATURAL SCIENCES AND MATHEMATICS
YEAR 2 PHYSICS
EXPERIMENT #15
TITLE: Radioactive Decay
AIM: To determine whether the volume of liquid left in an emptying burette follows an
exponential decay curve
APPARATUS/ MATERIALS: Stand, clamp, boss, 50 mL burette, beaker, colouring
DIAGRAM:
Clamp
Boss
Burette
Stand
Beaker
PROCEDURES:
1. Set up apparatus as shown in the diagram above.
2. With the tap closed, fill the 50mL burette with coloured water above the 0 mark to start
with a volume of 50 mL (Vo).
3. Open the tap, allowing the liquid to run out and falling into the beaker. Record the time
taken for the volume of liquid to fall from 0mL to 5mL.
4. The volume V remaining in the burette is also recorded.
5. Add more coloured liquid to the burette to bring the volume of liquid level back to 0mL.
6. Open the tap once more and record the time for the volume of liquid to fall from 0 mL to 10
mL.
7. Repeat this process for successive decreasing of 5 mL intervals, until the volume falls to
50mL.
CALCULATIONS:
1. Calculate and insert values for V/Vo and Ln(V/Vo) in the result table.
2. Plot a graph of ln(V/Vo) vs t and draw the best straight line through the points
3. Use evidence from the graph to justify whether the liquid (coloured water) decay is
exponential
RESULTS:
V (mL)
t (secs)
V/Vo
50
45
40
35
30
25
20
15
10
5
0
-, 5.48, 5.86
11.58,11.92
17.82,18.24
24.57,25.00
37.80,32.27
39.38,39.85
47.87,48.14
57.17,57.56
1:07:65,1:07:89
1:19:86,1:20:36
1
9/10
4/5
7/10
3/5
1/2
2/5
3/10
1/5
1/10
0
Ln(V/Vo)
END OF PRACTICAL