LAB 6 THE PENDULUM AND SIMPLE HARMONIC MOTION
In theis experiment, you will construct models of a simple pendulum using different masses and lengths of cord. For each model, you will measuee how long it takes the pendulum to complete 20 cycles. You can then use the period and the length of the cord to calculate g.
OBJECTIVES:
- Determine g.
- Verify the relationship between the period and the length of the cord.
- Verify the relationship between the period and the mass of the pendulum bob.
MATERIALS:
1 two meter long string
1 set of hanging masses
Procedure:
Constant mass with varying length:
1. Decide on your maximum and minimum lengths.
- Measure and record the mass used for the pendulum bob.
- Measure and record the length of the chord from where it is held down to the center of the mass. Hold the two ends of the string firmly against the edge of the lab counter, no more than a centimeter apart.
- Record the time it takes for 20 complete cycles of the pendulum swinging back and forth. Keep the angle of the swing no greater than 15°.from the vertical.
- Repeat steps 3 and 4 for a total of 5 trials.
Data table:
Prepare before the day of the lab.
Constant length with varying mass:
1. Decide on your maximum and minimum mass
- Measure and record the mass used for the pendulum bob.
- Measure and record the length of the chord from where it is held down to the center of the mass.
- Repeat steps 2 and 3 for a total of 5 trials, keeping the length of the chord from where it is held down to the center of the mass the same for all 5 trials. You may have to adjust the length in each case because of the differences in the length of each mass.
Calculations:
Show your calculations for the first trial.
Calculate g using the formula relating period to length and gravitational
acceleration.
Subtract to find the absolute error.
Divide by g = 9.8 to find the relative error.
Results Table:
Graphs:
Plot a graph of length versus period.
Plot a second graph of the square roots of the lengths versus period.
Analysis:
- Is your value for g reasonable? Explain.
- How does the period vary with mass?
- How does the period vary with length?
- What type of function would you say best describes each graph?
- What can you conclude from the two graphs
Conclusion:
Summarize findings and relate to objectives.