1.3 — Motion: Playing Catch – Part II

App Features

Using the motion lens students will:

• Use previously recorded performances.
• Create a path.
• Add height.
• Adjust ground height.

Expected Activity Time

• Total Activity Time: 45 minutes
• Introduction: 20 minutes
• Investigation: 20 minutes
• Discussion: 5 minutes

Materials and Prep

• iPad with the Playground Physics app
• Videos created by students in the app. Students should have done this as part of Lesson 1.2 – Fun with Motion. If Lesson 1.2 was skipped, have students record a video of two people in their group playing catch.
• Worksheet: Motion: Playing Catch – Part II

Activity

Introduction (20 minutes)

• Explain to students that when scientists study the world they need to have standard ways of describing things so that other scientists can understand their data and analysis. Tell students that they are going to be learning standard ways to describe motion so that as a class they can talk about the patterns they see in the motion of the ball while playing catch, and know that they are all talking about the same thing.
• Ask students what the word motion means. Take student suggestions and, as a class, come to the consensus that motion is an object’s change in position.
• Ask students what information might be important to document when talking about the motion of an object. Take students’ suggestions and record them on their board.
• Share with students that when talking about the motion of an object in physics, we want to make sure to document and record the speed of the object, the distance it travels, and the direction of motion.
• As a class, go through the three examples in the “Recognizing Motion” portion of the worksheet so that students are familiar with where to find the information displayed in the app and gain experience describing motion. If possible, project these worksheets at the front of the class and have students follow along on their own copies.

Investigation (20 minutes)

• Tell students that they are going to analyze the video they recorded in their group of two people playing catch.
• Provide iPads to groups of students. Students should be working in the same group and should use the same iPad so that they have access to the videos their group recorded.
• Have students pull up a video of two students playing catch. Each group should create a path of the motion by placing dots on the ball as it moves back and forth between the two students who are playing catch.
• Have students open the graph drawer so they can see the white arrow that points in the direction that the object they are tracking is moving. (In this case, the students are tracking the movement of the ball so the arrow will change directions based on the direction the ball is moving.) Turning on the slow motion feature (turtle button) may make it easier for students to see the direction change in relation to the video they are watching.
• Once students have annotated their video, have them describe the motion of the ball while playing catch by completing the “Describing Our Own Motion” section of the worksheet.

Discussion (5 minutes)

• Once students have completed the worksheet, ask them if there is any data that is important when thinking about the motion of the ball that was not included in the questions on the worksheet. Allow time for students to share their ideas to this question and to share anything else that surprised them about the motion of the ball in their video.
• Remember to check the “Parking Lot” of questions at the end of the class period. Remove any questions that have been answered and have students add any new questions that may have come up.

Answer Key: Recognizing Motion

1.
a) Speed: 0.6 mps
b) Distance traveled along the path: 0.2 m
c) Horizontal distance from the start: 0.2 m
d) Height from the ground: 1.62 m
e) Direction of motion (draw an arrow): →

2.
a) Speed: 3.6 mps
b) Distance traveled along the path: 2.6 m
c) Horizontal distance from the start: 1.18 m
d) Height from the ground: 1.14 m
e) Direction of motion (draw an arrow): ↑

3.
a) Speed: 0.5 mps
b) Distance traveled along the path: 8.4 m
c) Horizontal distance from the start: 4.64 m
d) Height from the ground: 0.53 m
e) Direction of motion (draw an arrow): ↗

Worksheet Previews