Explore Your Ideas

To answer the key question for the activity, you must deliberately change the length of a pendulum. Each set of partners in your class will use a different length pendulum.

Experiment: If the length of a pendulum increases, what happens to the time it takes to swing back and forth 10 times?

Before you do any experiment, you have to know how you will do it! As you learned in the last activity, the procedure you use is very important. Everyone will follow the exact same procedure, except for using a different length for the pendulum. Your teacher will demonstrate the procedure for you.

Read and follow the directions below very carefully. Because you don’t expect to measure an exact value, you will make four measurements of the time for 10 swings. You will then calculate the average as your best value. Take turns being the Timer and the Counter.

STEP 1 Timer: Use a meter stick to measure the length of the string in centimeters. Measure from the knot to where the washer is tied to the string.

On your record sheet, record your measurement in a data table like the one shown.