The Research Experience for Teachers Program /

Activity Title: “Distance vs. Displacement”

Introduction/Motivation: Students have a hard time realizing there is a difference between the distance an object moves and its total displacement. This activity is designed to help them visualize those differences. Using the program Scratch, students are introduced to basic computer programming commands. Within the Scratch environment students can manipulate the background, characters, and movements to find and reproduce coordinates and graphs.

Procedure

Background:

Distance is a linear measurement between two points. Total distance measurements can be easily found when one knows the starting point and the path an object travels. So we understand how far it is to walk from your classroom to the cafeteria and we can measure the distance easily.

Displacement is the measurement of how far an object has moved from its starting point. An objects distance and displacement can be the same if you measure leaving the classroom to the cafeteria. However if you return to the classroom the displacement will be zero because your final position is the same as your initial position.

Preparation:

Learning Scratch basics and setting up the background for the lab.

  • Using a web browser go to Click on the create tab to start.

(You do not have to create an account.)

Figure 1- Scratch Start page

  • Complete the Tutorial on how to use Scratch, it should take you less than 10 minutes. (If you cannot find the tutorial window after a step, click on the question mark at the right side of the screen.)

Figure 2 Scratch Tutorial

  • When done with the tutorial, go to file and select new for your project.
  • First we will set the background. Click on the Choose backdrop from library icon, then choose the Other Category and then click on the xy-grid to set the background. Use Figure 3 to help.

Figure 3 Change Background

  • When your project is open, you will be on the Motion command screen, click in the check boxes beside the x position and y position. Notice the Sprite Position labels appear in the upper left corner as in Figure 4.

Figure 4 XY Position Boxes

  • Now you are ready to complete the Distance and Displacement Lab Worksheet.

Lab Activity:

Distance and displacement using Scratch Worksheet (See attached file)

Assessment

Pre-Assessment

  • How do we measure distances?
  • What is the difference between distance and displacement?
  • Can distance be greater than displacement?
  • Can displacement be longer than distance?

Results/Conclusions

  • Students should turn in Distance and displacement using Scratch Worksheet.
  • Students should have used the graphs and be able to describe how distance and displacement are related and different.

Reference(s)

Scratch -

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