MnSTEP Teaching Activity Collection > MnSTEP Activities > Investigating Motion: Understanding Frame of Reference

# Investigating Motion: Understanding Frame of Reference

#### Summary

In this lab activity, students investigate the concept of frame of reference by observing, describing and drawing the same walking motion from different positions. Additionally, they determine the effect of frame of reference on the walking time. Students analyze their data and observations and develop a working definition of the concept of frame of reference. A description of the lab report format is provided.

## Learning Goals

This activity is designed for students to develop an understanding of "frame of reference". Skills developed: Lab Skills: a) practice measuring with stop watches and meter sticks, b) practice writing and drawing descriptive observations. Thinking skills: a) analysis of data and observations, b) synthesis of ideas, c) development of concept definition.
Key concepts: The motion of on object can be described.
An object in motion changes position.
How motion is perceived depends on your frame of reference.
Vocabulary words: frame of reference, motion, position, distance, displacement

## Context for Use

This lab activity is intended for grades 6 - 8 and is written for a class of 30 -35 students in groups of 5. However, it can be adapted for as few as 2 students or as a whole group demonstration. A 45 - 60 minute class period is necessary for all students to be able to participate in all roles. Stop watches, meter sticks, tape and 5 meters of walking space are needed. This activity will work best at the beginning of a unit on motion. It introduces the concept of frame of reference and gives practice using a stop watch to measure time and a meter stick to measure distance. The analysis questions help develop an understanding of experimental procedure and reflect on the reasons for multiple trials and sources of error.

Subject: Physics:Classical Mechanics:Relative Motion
Resource Type: Activities:Lab Activity

## Description and Teaching Materials

Students are divided into groups of 5. They use a meter stick and tape to mark off a walking track five meters long, putting down tape for a starting line and a finish line. One student becomes the walker (or runner, hopper, or skipper) and will walk backwards from the starting line to the finish line. Each of the other four students stands on one of the sides or ends of the track (representing four different frames of reference). When the walker begins moving, each observer begins timing and observing the motion. They
stop when the walker stops at the finish line. The walker records his/her time on the lab report and repeats walking for a total of three trials. After three trials, each observer completes question number 1 in the data section on his/her own lab paper, describing in words and pictures, the motion from his/her frame of reference. When data has been recorded, group members switch positions and continue observing and timing until each group member has been in each position, including the walking position. When all data has been collected, students complete the lab handout. Closure will consist of whole group comparison of the descriptions and drawings of motion for the different frames of reference; this could include role playing and commentary. The lab report questions are reviewed and a class definition of frame of reference is written based on student input. Lab Report (Microsoft Word 89kB May16 11) Data Table (Microsoft Word 47kB May16 11)

## Teaching Notes and Tips

- The major problem for this activity is finding space so students don't walk or hop, or jump into each other.
- When presenting the activity, I would have a group of students demonstrate the positions and activities to the entire class.
- Instead of individuals completing their own lab reports, one group lab report could be completed and shared.
- If you don't have enough floor space, have students sit around a table and roll a marble or matchbox car down a ramp.
- Calculating and comparing speeds can become an extension of this activity.

## Assessment

- While the teacher observes the groups, students can be asked to provide a commentary of the motion from their frame of reference.
- Drawings and descriptions can be presented at the classroom door as students leave (or the next day when they return) for a immediate check for understanding.
- Using pictures or video on an overhead or Smartboard, have students write a description of the motion from different frames of reference.
- Have students develop and share their own scenarios to use frame of reference to describe motion (football player running down field).
- Students write an article for Wikipedia describing frame of reference.
- Students are able to describe their own experiences in terms of frame of reference.

## Standards

6.II.D.1: The student will use a frame of reference to describe the position, speed and acceleration of an object.

## References and Resources

See more MnSTEP Activities »