Walking the Line: Using Motion Sensors to Graph Slope - Part 1

Traci Seto - Joseph Kerr Middle School

Subject Area - Math (Algebra)
Grade Level - Middle School

Overview: To make the abstract concept of the relationship between motion and slope more concrete, students will connect the everyday, physical activity of walking to a graphing activity.

Objectives:

• Students will make connections of slope (rate of change) of a line to motion of an object (distance vs time).

Procedure:

• Set up motion detector, overhead or document camera, and teacher workstation. Explain the hardware set up to students and give a brief explanation on how the motion sensor works. Pass out Student Worksheet 1.
• Explain possible student walking conditions:
1. Start at the CBR (motion sensor) and walk away at a slow steady rate.
2. Start at the CBR and walk away at a fast steady rate.
3. Start at opposite end of room and walk towards CBR at slow rate.
4. Start at the CBR and walk away at a slow steady rate at 3 meters stop for 2 seconds then walk at a faster rate to the end.
5. Start at the CBR and walk away at a fast steady rate, at 3 meters stop for 2 second then walk at a slow rate to the end.
6. Start at the CBR and walk away at a fast steady rate turn around at 4 meters and walk back towards CBR at a slow rate.
7. Start at the CBR and walk away at a slow rate speeding up over the 5-meter walk.
• Ask for student volunteers to demonstrate one - or a combination - of the above walking conditions. For each walk:
• have students describe the walk in words
• have students make a prediction about the graph and share their prediction
• have student volunteers walk according to the conditions in the teacher section.
• observe the graph of the motion and sketch the graph on the worksheet
• copy the data points information for student table
• calculate the slope (after the data has been collected of all walks)
• After students have made and shared predictions for each walk, project (on overhead or document cam) and discuss the graph.
• Use trace function to get 4 representative data points. Data points should be significant graph events (places where slope is changing). Note: slopes can be calculated after all of the motion information has been collected.

Note: This lesson has been adapted from a workshop by Gail Standiford for CMETS Middle Grades Summer Institute 2002.

Materials:

• TI83+ Teacher’s edition with overhead panel and motion detector
• Computer with TI Graph Link 83+ (optional)

Lesson Resources:

Standards

ISTE NETS:

• Collaborate with peers, experts, and others using telecommunications and collaborative tools to investigate curriculum-related problems, issues, and information, and to develop solutions or products for audiences inside and outside the classroom.
• Select and use appropriate tools and technology resources to accomplish a variety of tasks and solve problems.

Common Core Standards – Mathematics

• Grade 7 - Analyze proportional relationships and use them to solve real-world and mathematical problems
• Grade 8 - Understand the connections between proportional relationships, lines, and linear equations.
• Algebra I - Create equations that describe numbers or relationships; represent and solve equations and inequalities graphically.

California Content Standards for Mathematics