Pendulum and the Calculation of g

Hands-On Labs, Inc.
Version 44-0269-00-01

Lab Report Assistant

This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.

Data Table 1.Trial Values at Varying Degrees.

Length of string: cm = mMass of bob: g = kg

Placement of Bob Degrees / Amplitude (bob horizontal displacement) cm / Trial 1 (s)
5cycles / Trial 2 (s)
5cycles / Trial 3 (s)
5cycles / Avg. Time
(s)
5cycles / Period
1 cycle
5o
10o
15o
20o
25o
30o

Data Table 2.Trial Values for Bob Masses.

Length of string: cm = mAmplitude: 10°

Bob
weight
(g) / Bob
weight
(kg) / Trial 1 (s) / Trial 2 (s) / Trial 3 (s) / Avg Time (s) / Period

Data Table 3.Trial Values for String Length.

Mass of bob: g = kg Amplitude: 10o

Length (m) / Trial 1 (s) / Trial 2 (s) / Trial 3 (s) / Avg Time (s) / Period
.25
.50
.75
1.0

Questions

  1. How did the change in the weight of the bob affect the resulting period and frequency?
  1. How did the change in amplitude affect the resulting period and frequency?
  1. How did the change in length of the pendulum affectthe period and frequency?
  1. What would happen if you used very large amplitudes? Check your hypothesis by trial. What amplitude did you use? What is the result?
  1. Hypothesize about how a magnet placed directly under the center point would affect an iron bob? Try it and find out. Did your trial verify your hypothesis?
  1. How close was your calculation of the value of g at your location? What might be a few sources for error in your experimental data and calculations?
  1. What would you expect of a pendulum at a high altitude, for example on a high mountain top? What would your pendulum do under weightless conditions?