The Mad Scientist

Pendulums:

Does Length affect Frequency?

In this experiment, we will try to answer the question, "Does the length of the pendulum affect its frequency?"

Materials:

Pendulum support	paper clip
1" wooden bob	halved golf tees
string	ruler and paper ruler

Procedures:

1. Assemble a 50 cm pendulum. Be sure to measure to the middle of the bob. See the figure below.

2. Predict how many cycles your pendulum will make in one minute. Record your prediction on a chart like the one below.

3. Start the pendulum swinging from an amplitude of 20 cm. Even though the previous experiment showed that amplitude does not affect frequency, use this same pullback distance for the entire lesson. It is a constant.

4. Count the cycles per minute and record this as your actual observation on the chart. You can count the number of cycles for 15 seconds and then multiply by four to calculate the frequency (cycles per minute).

5. Repeat this procedure with different pendulum lengths. Be sure to record the length, predictions and the actual observations on the chart.

6. Look at the information you collected to help you explain how the length of the pendulum affects the frequency of the pendulum.

Teacher's Notes | Glossary | Experiments | Mad Scientist | Oak View Elementary