Pendulum
Lab Name
_____________________________
Purpose: To investigate the motion
of a pendulum and determine what affects its rate of swing.
The
period of a pendulum is the time it takes to make one complete swing. Measuring
just one swing is difficult, so we are going to time 20 swings, and divide by
20 to determine the time for one swing. Remember to measure complete swings.
We
will investigate three factors; the length of the string, the mass of the
pendulum, and the distance it is pulled back. We will see which of these
affects the period of the pendulum.
Materials and Equipment:
Ring
and Ringstand Meter
stick String Weights Stopwatch
Procedure:
Part
I - The effect of different distance pulled back
1. Tie the string to the ring
stand and to the 200 g weight, so that the weight hangs 40 cm from the ring.
2. Pull weight back 10 cm and
time how long it takes to make 20 swings.
3. Repeat this 2 more times.
4. Pull the weight back 20 cm
and time how long it takes to make 20 swings.
5. Repeat this 2 more times.
6. Pull the weight back 30 cm
and time how long it takes to make 20 swings.
7. Repeat this 2 more times.
Part
II - The effect of different masses.
8. Tie the string to the ring
stand and to 200 g weight, so that the weight hangs 40 cm from the ring.
9. Pull weight back 10 cm and
time how long it takes to make 20 swings.
10. Repeat this 2 more times.
11. Attach the 500 g weight,
keeping the string the same length. Pull weight back 10 cm and time how long it
takes to make 20 swings.
12. Repeat this 2 more times.
13. Attach the 1000 g weight,
keeping the string the same length. Pull weight back 10 cm and time how long it
takes to make 20 swings.
14. Repeat this 2 more times.
Part
II - The effect of different string lengths.
15. Tie the string to the ring
stand and the 200 g weight, so that the weight hangs 40 cm from the ring.
16. Pull weight back 10 cm and
time how long it takes to make 20 swings.
17. Repeat this 2 more times.
18. Tie the string to the ring
stand and the 200 g weight, so that the weight hangs 30 cm from the ring
19. Pull weight back 10 cm and
time how long it takes to make 20 swings.
20. Repeat this 2 more times.
21. Tie the string to the ring
stand and the 200 g weight, so that the weight hangs 20 cm from the ring
22. Pull weight back 10 cm and
time how long it takes to make 20 swings.
23. Repeat this 2 more times.
24. Tie the string to the ring
stand and the 200 g weight, so that the weight hangs 80 cm from the ring.
25. Pull weight back 10 cm and
time how long it takes to make 20 swings.
26. Repeat this 2 more times.
Hypothesis:
Before
you begin the lab, answer the following questions.
1. What do you think the effect
of pulling back further will be on the period of the pendulum and WHY?
2. What do you think the effect
of adding more weights will be on the period of the pendulum and WHY?
3. What do you think the effect
of lengthening the string will be on the period of the pendulum and WHY?
Conclusion:
Answer
the following questions AFTER completing the laboratory.
4. Describe the effect pulling
the weight back further had on the period of the pendulum.
5. Describe the effect adding
weights had on the period of the pendulum.
6. Describe the effect a longer
string had on the period of the pendulum.
7. Were your hypotheses
supported by this experiment? Explain your answers.
Data
Tables
Part
I
|
Distance Pulled Back |
Time
for 20 swings |
Average |
Period for one swing |
|
|
10 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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20 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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30 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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Part
II
|
Weights |
Time
for 20 swings |
Average |
Period for one swing |
|
|
200 g |
Trial
1 |
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Trial
2 |
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Trial
3 |
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500 g |
Trial
1 |
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Trial
2 |
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Trial
3 |
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1000 g |
Trial
1 |
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Trial
2 |
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Trial
3 |
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Part
III
|
Length of String |
Time
for 20 swings |
Average |
Period for one swing |
|
|
40 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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30 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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20 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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80 cm |
Trial
1 |
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Trial
2 |
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Trial
3 |
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