# Motion and Variables

### Pendulums

## Materials

- Strings at different lengths
- Pennies
- Paper Clips
- Number Chart
- Pencils
- Stopwatch

## Steps in the Lesson

1.Have students tape a pencil 5 cm from their desks.

2.Pass out materials to each group: pennies, stopwatch, strings of different lengths, paper clips, masking tape, and a ruler.

3.Students will connect the paper clip to the strings and adding a penny to the paper clip to create their pendulums.

4.Students will measure out the lengths of their strings in the following degrees: 13 cm, 17 cm, 20 cm, 25cm, 33cm, 55 cm, 90 cm, 170 cm.

5.After they measure out each length, have them make a loop at the end of the string and tape the loop in place.

6.Students will test their hypothesis of how many swings the pendulum will make in 15 seconds. Record answer in data table

7. Students will create their standard with a length of 38 cm.

8.Have students make their predictions of the amount of swings the pendulum will make when changing the release positions.

9.Students will test their release position changing from 0 to 45.Set stopwatch for 15 seconds and record data.

10.Students will change the **mass** of the pendulum by adding **two** pennies to a single paper clip. Have students make predictions of number of swings and record data.

11.Set stopwatch for 15 seconds and record data.

12.Students will then make **six** changes in **length.** They will go back to **one** penny and use the different lengths of strings.

13.They will make predictions of how many swings the pendulums will complete for each length and test their hypotheses using the stopwatch for 15 seconds.

14.Tape the number chart on a wall in the classroom and have each group hang their pendulum under the number of swings completed.

## Analysis of Data

## Teaching Notes

Scaffolding

To test student's knowledge after the experiment, have them journal their answer to the question "How does changing the mass, length, or release position effect the number of swings the pendulum completes in a unit of time?" Using a concept map on cause and effect can also assess their understanding of this experiment. This can allow the teacher to information needed to determine if there needs to be any reteaching done.