Hands-on Activity Save the Stuffed Animal!
Push & Pull

Learning Objectives

After this lesson, students should be able to:

• Define the terms "push" and "pull."
• Apply the concepts of "push" and "pull."
• Use EV3 robots to help illustrate the concepts of "push" and pull."

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• 1 EV3 basic robot (Note: LEGO MINDSTORMS EV3 robot, such as EV3 Core Set (5003400) at https://education.lego.com/en-us/products/lego-mindstorms-education-ev3-core-set/5003400#lego-mindstorms-education-ev3; instructions to build and program a basic robot are included with the robot kit; a sample program for "pushing" and "pulling" is attached to this activity; if not enough robots are available for one per group, share among several groups or the class by taking turns with the robot.)
• 1 stuffed animal
• string or yarn to make a secure loop around the stuffed animal, and a hook (make one by bending a paper clip) (Note: This is to attach to the robot so the robot can pull the stuffed animal.)
• Pre-Activity Content Assessment, one per student
• Post-Activity Content Assessment, one per student

Note: This activity can also be conducted with the older (and no longer sold) LEGO MINDSTORMS NXT set instead of EV3; see below for those supplies:

• LEGO MINDSTORMS NXT robot, such as EV3 Base Set

Worksheets and Attachments

Pre-Req Knowledge

Basic familiarity with EV3 robots and EV3 robot programming

Introduction/Motivation

Discussion & Lecture with Students

Force is a very important concept in science and engineering. Two common examples of force that you may have heard of are "pushing" and "pulling." Raise your hand if you have heard of these words before. (Observe students raising their hands.)

Great! Now, raise your hand if you can either tell me or show me what "pushing" means?

(Select students to state or demonstrate their definition until a correct definition and demonstration have been given. Then emphasize this correct definition by repeating it, and demonstrating it visually. For example, move your arms in front of yourself, and mimic pushing forward with great difficulty. Ask students to confirm that you are pushing. Repeat this as necessary until students understand the concept of pushing.)

Wonderful. Now, raise your hand if you can either tell me or show me what "pulling" means? (Select students to state or demonstrate their definition until a correct definition and demonstration have been given. Then emphasize this correct definition by repeating it, and demonstrating it visually. For example, move your arms in front of yourself, and mimic pulling something backwards with great difficulty. Ask students to confirm that you are pulling. Repeat this as necessary until students understand the concept of pulling.)

Fantastic! Now, who can tell or show me what the difference between pushing and pulling is? (Select students to state or demonstrate this distinction until it has been done correctly.)

Okay! Today, we're going to see how important it is to know these words, and the difference between them! We're going to help save a cute stuffed animal from falling off a table, by either choosing to push or pull the stuffed animal to safety. Better still, we're going to use a robot to carry out our decision! Our robot has been programmed to either push a certain distance, or pull a certain distance. Once we attach our stuffed animal to our robot, you'll be able to decide whether a push or a pull would be the best choice to bring the animal to safety. Would you like to meet our robot and our stuffed animal? (Wait for response, then display each.)

I'm going to show you an example of how this robot can push and pull our stuffed animal, so you can see how easy it is! (Briefly demonstrate pushing the stuffed animal with the robot, and pulling the stuffed animal with the robot.)

We want to try our best to keep our stuffed animal from falling off the table by either pushing or pulling it to safety, but don't be too upset if during the course of today's activity it does fall. The stuffed animal won't be hurt, and I'm sure if it thought about the important concept you're learning, it would understand. Are we ready to start? Great!

Procedure

Background

During the activity, students observe a series of demonstrations in which the robot either pushes or pulls a stuffed animal. They are responsible for recognizing when the robot is pushing and when it is pulling the stuffed animal and ultimately decide whether the robot needs to push or pull the stuffed animal to safety. Have students work in pairs, and give each group a turn at each part of the activity. When one group is having its turn to program the robot, with the teacher's assistance, the other groups should be observing each demonstration and discussing what they see. If wait time between turns is any longer than five minutes, ask student groups to draw the set-up when the robot needs to push the stuffed animal and draw the set up when the robot needs to pull the stuffed animal. Require students to label their drawings and include arrows showing what direction the robot and stuffed animal will move.

Before the Activity

• Read the LEGO instructions for how to build and program a basic robot (included with the LEGO MINDSTORMS EV3 robotics kit. Then, practice programing the robot using the Sample Pushing Program (see Figure 1) and the Sample Pulling Program (see Figure 2). During the activity, help student groups to program the robot to either push or pull.

  

  

• Administer the Pre-Activity Content Assessment to students and collect when finished.
• Discuss the concepts of push and pull, as outlined in the Introduction/Motivation section.

With the Students

Part 1: Practicing Pushing and Pulling and Identification

Pushing

1. Help each student group program the robot using the Sample Pushing Program.
2. Have student groups place the robot behind a stuffed animal, facing toward it.
3. Allow the robot to run for its distance program.
4. Ask student groups whether or not the robot pushed or pulled the stuffed animal.

Pulling

1. Help each student group program the robot using the Sample Pulling Program.
2. Have student groups place a robot in front of a stuffed animal and attach it with a hook.
3. Allow the robot to run for its distance program.
4. Ask student groups whether or not the robot pushed or pulled the stuffed animal.

Teacher Mystery Choice

1. Have students observe a demonstration of the robot and stuffed animal interacting.
2. Ask students to decide with their partners whether or not the robot pushed or pulled the stuffed animal. Call on students to share their answers.

Part 2: Save the Stuffed Animal!

Which way to Safety?

1. For each student group, set the stuffed animal and robot close to the edge of a table. Choose a slightly different position for each group.
2. Ask students groups whether the robot should "push" or "pull" the stuffed animal to safety based on its position.
3. Allow the robot to carry out the decision student groups made.
4. Have students observe what happened to the stuffed animal. Ask them the following questions: Did it get out of danger? Or did it get into more trouble? Would you choose differently if you had to do it again?

Vocabulary/Definitions

force: Movement of an object.

pull: Moving an object toward oneself.

push: Moving an object away from oneself.

Assessment

Pre-Activity Assessment

Students complete the Pre-Activity Content Assessment to demonstrate their prior knowledge of pushing and pulling.

Activity Embedded Assessment

Circulate through the room during the activity, working with each group. By observing, helping and ask questions, assess students' understanding of the concepts of "push" and "pull."

Post-Activity Assessment

At activity end, have students complete the Post-Activity Content Assessment to demonstrate what they understand about pushing and pulling. Make a comparison to their results of the Pre-Activity Content Assessment to evaluate what students gained from the activity.

Investigating Questions

• What does "push" mean?
• What does "pull" mean?
• Can you identify pushing vs. pulling when you see examples of each?

Troubleshooting Tips

Ask students not to practice pushing or pulling on each other, because this may upset fellow classmates.

If students become restless while waiting for their turns, ask them to make drawings of the set-up, as described in the Procedure > Background section.

Activity Scaling

• For lower grades, emphasize the concepts of push and pull through demonstrations and put less emphasis on students defining the concepts in words.
• For higher grades, place greater emphasis on applications that require the use of a pushing force or a pulling force. Discuss and ask student to brainstorm different things engineers design and build that rely on a firm understand of forces.

Copyright

Contributors

Supporting Program

Acknowledgements

This activity was developed by the Applying Mechatronics to Promote Science (AMPS) Program funded by National Science Foundation GK-12 grant no. 0741714. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.