Objects move in different ways during physical activities on the playground.
Develop a model showing how the strength and direction of a force can cause an cause an object to move.
A basketball on the playground moves when it is thrown.
Click here for NGSS, CCSS–ELA, and California ELD standards.
This lesson builds on students’ prior knowledge shared in Lesson 1: Movement on the Playground. In this lesson, students explore the cause and effect of various characteristics of forces using the game of basketball. Students create a model to show that forces have strength and direction. Students are also introduced to the force of gravity.
In the next lesson, students analyze data to determine patterns and predictability of motion and apply their analysis to their engineering challenge.
Throughout the lesson, a flag () denotes formative assessment opportunities where you may change instruction in response to students’ level of understanding and making sense of phenomena.
The next 3 lessons will be working on three-dimensional learning. SEPs include models in Lesson 2: Forces Move Objects, and analyzing data/arguing from evidence in Lesson 3: Patterns of Motion, and models in Lesson 4: Balanced and Unbalanced Forces. CCCs include cause & effects throughout and building on patterns in Lesson 2: Forces Move Objects to predictability in Lesson 3: Patterns of Motion and Lesson 4: Balanced and Unbalanced Forces. The DCIs for force and motion include: strength and direction, patterns and prediction of movement, and balanced and unbalanced forces. Strength, direction, patterns, and predictability are emphasized in Lesson 2: Forces Move Objects and Lesson 3: Patterns of Motion; balanced and unbalanced forces are used in Lesson 2: Forces Move Objects and Lesson 3: Patterns of Motion culminate in Lesson 4: Balanced and Unbalanced Forces.
In Lesson 2: Forces Move Objects and Lesson 3: Patterns of Motion the focus is on using balls to experience the basic concepts of force and motion. In Lesson 4: Balanced and Unbalanced Forces, the understanding of these forces is applied to a non-ball activity, a tug-of-war. This physical experience of balanced and unbalanced forces resonates with third graders who think about balance as not falling down. In the tug-of-war, when students slide or fall, it physically represents the idea of unbalanced forces.
Using different experiences of motion (i.e. a ball that is thrown, a ball that is kicked, and tug-of-war) allows students multiple opportunities to gain an understanding of third-grade concepts of forces and motion.
Although there is a zero net force discussion in this lesson in terms of equal forces acting on an object, a deeper discussion of zero net force is a middle school disciplinary core idea.
Part I | 60–120 minutes | Engage |
Part II | 60–120 minutes | Explore/Explain 1 |
Part III | 10–20 minutes | Explain 2 |
Part IV | 30–60 minutes | Elaborate |
Part V | 30 minutes | Evaluate |
These activities/references can extend understanding of force and motion:
Develop a model showing how the strength and direction of a force can cause an object to move.
Find an example from a science notebook that has arrows showing motion and possible forces acting on the basketball. You will use this sample, under the doc camera, to facilitate a discussion on what might be needed in a model to represent motion and possible forces acting on an object.
Features of a model include identification and labeling of the parts, how the parts relate to one another, and how the model can be used to make a prediction or explanation. These features will be explored throughout the rest of the lesson using 3.2.C1: Observable Features of Models.
When thinking about force and motion, scientists use labels and arrows to show the direction of the force (cause) to an object and the strength of the force causing the object to remain in place or move (effect). They add supporting details to better explain what is happening.
Not all of the students were able to draw a basketball on 3.1.H1: Motion Observation. This gives all students the opportunity to draw a model of a basketball. Encourage students who drew a basketball on 3.1.H1: Motion Observation to transfer their model of the basketball from the ground onto a desk and label it.
There will be many steps in the scaffolding of “creating a model” within this lesson. Students will be given multiple opportunities to revise and add to models throughout this lesson. Therefore, basic models without details representing or explaining cause-and-effect relationships are acceptable at this time.
As students revise their models, notice how their thinking is changing both in terms of developing models (i.e., the Observable Features of Models) and using models to describe the scientific concepts.
Encourage the student to push the ball so that it falls off the desk. This gives students the chance to add it falling in their model. At this time students might not mention gravity.
Students should discuss push and pull which they learned in kindergarten. They may bring up the word force. If they do, you should discuss its meaning. If they don’t bring up this word, you can use it in relation to their model by saying, “Do you know what a scientist calls a push or a pull? They are both called a force.”
Students are not expected to draw different size arrows to indicate the strength of the force at this time. Force/strength arrows will be added later in the lesson.
Students are not expected to be able to explain equal forces or gravity at this point, but it will be made explicit in the class model that follows. They may mention that a force is “pulling the ball down.”
It is important for students to understand that an object at rest typically has multiple forces acting on it and that these forces are equal or balanced. Most likely students will use the word equal. If they do, introduce that equal forces are balanced. Use the leading questions above to facilitate this discussion.
It is not necessary to explain gravity at this point (it will be explained at the middle school level). Only label it as the force that pulls down. Also, point out that it is a force that causes motion without contact.
At this point label (or confirm) that the downward-pulling force is called gravity. Explain that this force pulls things down. Also, point out that gravity is a force that causes motion without contact.
Develop a model to describe movement on the playground, noting what causes the movement.
Make sure the circled questions support the students’ understanding that the strength and direction of forces can cause a basketball to move and how balanced and unbalanced forces impact that motion. If the questions do not allow for this, add several of your own questions that do.
If your students are not ready to work independently, you may want to have one group model the activity while the other students record observations. Allow student teams to take turns with the activity.
If time, or lack of available playground equipment, does not allow for the class to participate with the basketball, you can show Boys Outside Shooting Hoops video instead. Stop the video at 20 seconds (repeat if necessary).
Obtain and communicate information describing characteristics of forces and the cause and effect of force on motion.
When selecting a book or reading passage from the recommended list:
You may choose to have students share selected sentences with the whole class. Write them on sentence strips. Group similar sentence strips that support learning concepts on the wall as a visual summary of the reading. These can be referenced throughout subsequent lessons as needed.
Using the characteristics of forces and their effects on motion, design a solution for a new piece of playground equipment or activity.
You may add any other constraints you want to this investigation.
Communicate information describing patterns of movement on the playground.
force | balanced or unbalanced |
ball | equal |
gravity | cause and effect |
The question is designed so that students who really understand force and motion would both agree and disagree with the statement based on balanced and unbalanced forces, and strength and direction of forces.
ReadWorks (Online Passages available at www.readworks.org)
Boothroyd, J. (2011). Give it a push! Give it a pull!: A look at forces. Minneapolis, MN: Lerner Publications Company.
Frost, A. (2013). Making things move: Force and motion. New York, NY: Rosen Classroom.
Manolis, K. (2009). Motion. Minneapolis, MN: Bellwether Media.
PhET. (n.d.). Force and Motion: Basics. Retrieved from https://goo.gl/vUQW4E
Phoenix Film and Video. (n.d.). Gravity, Force and Work. Retrieved from https://goo.gl/ix3fkD
ReadWorks. (n.d.). Retrieved July 20, 2020, from http://www.readworks.org/
Sid the Science Kid. (n.d.). Retrieved July 20, 2020, from https://pbskids.org/sid/
Smart Learning for All. (2014, December 27). Force, Work, and Energy. Retrieved from https://goo.gl/eYCCvp
Stem Teaching Tools. (n.d.). Talk Science Printable. Retrieved from http://stemteachingtools.org/assets/landscapes/TalkSciencePrintable.pdf
Stewart, M. (2003). Motion. Minneapolis, MN: Compass Point Books.
Twhite, K. (2015, January 19). Boys Outside Shooting Hoops. Retrieved from https://www.youtube.com/watch?v=-3m202OMCsI
Veritasium. (2011, February 17). What Forces Are Acting On You? Retrieved from https://goo.gl/WjZ27X