### Diane SchmidtFlorida DOE

#### Description

The students conduct an inquiry-based investigation to generate, collect, organize, analyze and display data in order to determine the effect of net force on an object.

#### Objectives

The student knows that an object may move in a straight line at a constant speed, speed up, slow down, or change direction dependent on net force acting on the object.

The student knows that it is important to keep accurate records and descriptions to provide information and clues on causes of discrepancies in repeated experiments.

#### Materials

- One large marble, and one small dried pea
For each group provide:
- Ruler or other item that can be used as a ramp.
- Several books or objects to hold up one end of the ramp
- Marble or other small sperical objects (ie: rubber ball, golf ball, ping pong ball, wooden bead, ball beering, etc.)
- Metric measuring tape
- calculator
- Paper and Pencil
- Graphing software such as Excel
For each student:
- Data Sheet (See Attached File)
- Graph Paper
- List of NASA websites (see Weblinks)
Technology:
- Projection system (if using one computer to present the NASA website)

#### Preparations

1. Gather Material
2. Divide and package materials in reclosable plastic bags.
4. Copy recording sheets
5. Prior instruction on the -averaging-
5. Prior instruction on creating graphs
6. Prior instruction on using graphing software

#### Procedures

Engaging Activity (5 minutes)
1. The teacher begins the lesson by holding both a marble and a small pea, at the same distance from the ground.

2. Have students predict which one will reach the ground first.

3. Record the number of predictions for each on the board, overhead, or chart paper.

4. Drop the the marble and the pea, simultaeously.

5. Ask which landed first. (You may find disagreement.)

6. Ask if the results would be different if we dropped them from a higher point, such as the roof of the school. Allow discussion, but don't push for understanding or correct answers at this point.

Pre-Investigation Activities (10 minutes)
7. Divide the class into groupsof 3-5 students. Divide up responsibilities of reading directions, recording data, managing material, measuring, releasing objects (make necessary adjustments for group size).

8. Ask students predict if the height of a ramp will affect how far an object will travel. (Have them record their predictions and reasons without discussion)

9. Allow students to discuss their predictions in their groups.

10. Ask one person from each group to share their group's ideas.

Investigation (20 minutes)
11. Instruct students to use the materials provided to design an experiment to test their beliefs.

12. Instruct them to test the distance the object travels when released from three different heights on the ramp. (You may give heights such as 5, 10, 15 cm or allow students to select 3 heights.) Remind students to test each one at least three times to obtain an average.

13. Have one student record the average distance for each height.

Data Analysis (20- 30 minutes)
14. Each student should create a graph on paper an/or using computer software.

15. Have each student give an explanation of how ramp height affected the distance an object traveled (in writing or orally).

Follow-Up Options (10-20 minutes)
* Ask each group to present their graph and explain their conclusions.
* Ask how this related to the pea and marble dropping activity we did before the investigation?
* Discuss the experimental design factors, asking such questions as: How was your group information similar or different than the other groups? What may have contributed to those differences or similarities?
* Ask students where they have seen this concept in the real world.
* Have students visit the NASA websites to gain further information on the topic.
* Ask students what other questions they may have regarding these concepts, and discuss how they might find the answers to their questions (further experimentation, research, observation). For research questions, elicit a list of resources that they might use (non-fiction books, internet, encyclopedia, science textbook, expert in the field, etc.)
* Ask students to assess how well they worked together as a group. Use the questions listed in the assessment section.

Additional questions that may be discussed:
Did the objects travel in a straight line? Why or why not?
What caused them to change direction?
Why did some groups get different results than other groups? (Distance will increase with height until the incline exceeds 45 degrees. At this point the distance will decrease.)

#### Assessments

Formative assessment
- Observe and informally assess students' ability to work cooperatively to complete the experiments. The teacher should note whether students are completing their assigned tasks, but also observe how they function as a team. Are they all contributing ideas? Are they listening to one another? Are they taking turns speaking? Are they providing assistance to one another? Use these questions to guide students in the self-assessment of their group. (Cooperative Workers)
- Informally assess students' ability to clearly communicate their findings to the class. Students communicate in written, oral, and graphic form, they use appropriate language to convey factual information, and communicate using technology (graphing program or spreadsheets, and overhead transparencies) Make sure students are using eye contact and speaking slowly. (Effective Communicators)
-Assess whether students discuss their findings related to the concepts of direction, speed and force. Students should make a general statement regarding the relationship between force and motion, specifically how ramp height affects distance traveled. Do they recognize gravity and friction as forces contributing to the outcomes of their investigations?
-Assess whether students are able to identify discrepancies between group results in relation to variables, measurement techniques, and data collection process. (Critical and Creative Thinkers)

#### Extensions

-Conduct follow up experiments on force and motion based on the students' questions.
-Provide time for students to research questions that cannot be answered through experimentation.
-Suggested reading: [What Makes Things Move by Althea, and Energy and Force] by Terry Jennings.