August 17th, 2016

In this lesson, students revisit the writing they did at the beginning of the unit to add in more details and demonstrate all that they have learned about forces.

2.4 Force jumping

2.7 — Force: Double Dutch

App Features

Note that the Playground Physics app is not required for this lesson.

Expected Activity Time

  • Total Activity Time: 45 minutes
  • Introduction: 10 minutes
  • Investigation: 20 minutes
  • Discussion: 15 minutes

Materials and Prep

  • Force: Odd One Out Worksheet
  • iPad with Playground Physics app (optional)


Introduction (10 minutes)

  • Remind students that as a class you have been investigating the question “How can I describe the forces on my body when I jump rope with a friend?”
  • Pass back to students the worksheets that you collected from them during the first lesson, Force: Jumping Rope Part I.
  • Have students read what they wrote for the definitions of the vocabulary words and the explanation of jumping rope on their worksheet at the beginning of the lesson.

Investigation (20 minutes)

  • Pass out the worksheet Force: Double Dutch.
  • Allow students time to reflect on what they have learned and to complete the worksheet.

Discussion (15 minutes)

  • Allow students to share how their ideas about the forces involved with jumping rope have changed since they first wrote their narratives.
  • Encourage students to share their reflections about the process of practicing science. What do they feel they have learned about doing science from this investigation and through the use of the Playground Physics app?
  • As a class, revisit the “Parking Lot” of questions. Any questions remaining in the parking lot that have been answered can be removed. Any new questions that students have now that they know more can be added to the “Parking Lot”. Provide post-in notes and allow students to add any questions they have.
  • If students want to explore their remaining questions or new questions in more detail, Lesson 0.4 Science Investigation can be used to help structure these investigations.

Worksheet Previews

Screen Shot 2016-08-18 at 12.30.40 PM Screen Shot 2016-08-18 at 12.30.47 PM Screen Shot 2016-08-18 at 12.31.03 PM

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Big Idea

The purpose of this activity is to help students connect their initial lived experiences and ideas to their new knowledge about how physicists talk about forces.

The writing component of this lesson is designed as a formative assessment to show what students have learned about forces during the unit. Students should show an improvement in their abilities to describe forces, Newton’s Third Law of Motion, and Force Pairs.

Learning Objectives

  • Students will be able to use their observations and analysis of the forces involved with jumping rope to expand on their previously written narrative.
  • Students will be able to incorporate the vocabulary from this unit into their writing.
  • Students will reflect on the process of practicing science.

Standards Addressed


Crosscutting Concepts: Patterns

Observed patterns in nature guide organization and classification, and prompt questions about relationships and the causes underlying them.

Disciplinary Core Ideas

PS2.A: Forces and Motion

For any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in the opposite direction (Newton’s Third Law).

PS2.A: Forces and Motion

All positions of objects and the directions of forces and motions must be described in an arbitrarily chosen reference frame and arbitrarily chosen units of size. In order to share information with other people, these choices must also be shared.

Science and Engineering Practices

Engaging in Argument from Evidence

Construct; use and present oral and written arguments supported by empirical evidence and scientific reasoning to support or refute an explanation or a model for a phenomenon.

Scientific Knowledge is Based on Empirical Evidence.

Scientific knowledge is based on logical and conceptual connections between evidence and explanation.


Range of Writing

CCSS.ELA-LITERACY.WHST.6-8.10: Write routinely over extended timeframes (time for reflection and revision) and shorter time frames (a single sitting or a day or two) for a range of discipline-specific tasks, purposes and audiences.

English Language Arts: Writing

CCSS.ELA-LITERACY.WHST.6-8.2: Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments or technical processes.

Text Types and Purposes
CCSS.ELA-LITERACY.W.6,7,8.1: Write arguments to support claims with clear reasons and relevant evidence.

CCSS.ELA-LITERACY.WHST.6-8.2.D: Use precise language and domain-specific vocabulary to inform about or explain the topic.

Standard 4: The Physical Setting

PS 5.1c: An object’s motion is the result of the combined effect of all forces acting on the object. A moving object that is not subjected to a force will continue to move at a constant speed in a straight line. An object at rest will remain at rest.

PS. 5.1a: The motion of an object is always judged with respect to some other object or point. The idea of absolute motion or rest is misleading.

PS. 5.1b: The motion of an object can be described by its position, direction or motion, and speed.

PS 5.1q: According to Newton’s Third Law, forces occur in action/ reaction pairs. When one object exerts a force on a second, the second exerts a force on the first that is equal in magnitude and opposite in direction.


  • Force is an interaction between objects that causes  a change in the motion of an object.
  • Newton’s Third Law of Motion explains that for every action, there is an equal and opposite reaction.
  • Force pairs (push/pull) are the two objects whose forces are acting on one another in equal strength and opposite directions. These forces can be in the form of a push or a pull.