Total Duration: 
Greater than 120 Minutes 
Materials and Resources: 
string (at least 3 different types, such as fishing line, yarn, rulers or rods to use as rigid pendulums, etc.) tape pencils paper clips washers of different sizes or pennies measuring tapes or rulers (one for each group of 4 students) Graphing Sheets from FOSSweb (print and copy p. 3 "Making a Swinger" for each group of 4 students; p. 5 "Swingers Picture Graph" for each student, and p. 7 "Swingers TwoCoordinate Graph" for students you plan to accelerate) grandfather clock or clock animation displayed on screen chart paper or board for recording student responses Grandfather's Clock story from Everyday Science Mysteries (You can read this aloud to students or print student copies for use as a guided reading activity.) pendulum vocabulary sheet (can be used for teacher background and/or student use) index cards with the following lengths labeled: 17 cm, 18 cm, 25 cm, 30 cm, 38 cm, 50 cm, 70 cm, 90 cm, 120 cm 
Technology Resources Needed: 
projector and screen or interactive whiteboard for displaying presentation / images from Internet Websites: 
Background/Preparation: 
A pendulum is a weight attached to a string or rod that can swing freely from a fixed point. Swings, grandfather clock pendulums, and metronomes are pendulums students may encounter in their everyday lives. While students may have seen pendulums in the past, they probably have not thought about the variables that can affect the speed of a pendulum's swing. They will likely theorize that the weight on the end of the pendulum or the release position affect the speed of the pendulum, but after experimenting they will realize that the only variable that affects the speed is the length of the string. Once students have accepted this through experimentation, they will collect data about the number of swings a pendulum makes as the length of the string changes. They will then graph the data to predict the movement of pendulums not actually tested. Finally, they will use this information answer a realworld problem. You may want to view this FOSSweb video for additional background information about preparing pendulums. 
Note: Vocabulary words in bold are defined on the attached Pendulum Vocabulary sheet. ENGAGE (15  20 minutes  Choose the option that best meets the needs of your students): Option A: Solving a RealWorld Problem with Swings
Option B: Solving a RealWorld Problem about a Grandfather Clock
EXPLORE (20  30 minutes if each group only tests one variable, up to 2 hours if each group tests each variable at stations): For the exploration, you can either let each group decide on one variable to test or have all groups rotate through four stations to test each of the variables. The plan below is written assuming that each group will only test one variable, but your data will be more accurate if all groups test each variable in stations. Students will have a better understanding of variables and the experimental process if they test each variable, but you can “divide and conquer” for the sake of time if necessary!
EXPLAIN (30  40 minutes):
ELABORATE (15 – 20 minutes):

Attachments: **Some files will display in a new window. Others will prompt you to download. 
Assessment Strategies 
EVALUATE (10 minutes): Formative evaluation is ongoing during the experiments, but the culminating formative assessment for the lesson is an exit slip. Students should use their data to write a prediction for the length of a pendulum that would swing 11 times in 15 seconds. (If one of the tested pendulums swung 11 times, choose a number that does not have any pendulums so students will have to predict an unknown movement based upon their data.) They must use the graph as evidence to explain their prediction. Have students staple their explanations to the graph to turn in.

Acceleration: 
ACCELERATE – Students who have mastered bar graphing and data analysis can graph the data using a coordinate grid (see FOSSweb handout p. 7 “Swingers TwoCoordinate Graph”). Have them compare/contrast this graph to the bar graph. Are their predictions the same regardless of which graph they use? What are advantages and disadvantages of each graph? Students may also use the online tools (PBS and PHet sites listed in the technology resources section) to experiment with pendulums virtually. 
Intervention: 
INTERVENTION – Some students may need teacher assistance gathering accurate data. Common mistakes are inaccurate measurement of the length of the pendulums, changing more than one variable at the same time, inaccurate timing, and inaccurate counting due to a misunderstanding of cycles. By circulating among the groups as they experiment, you will be able to assist students with these difficulties. Students who struggle with graphing may benefit from working with a partner for the graphing component.

View the Special Education resources for
instructional guidance in providing modifications and adaptations
for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.
