### 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.