MnSTEP Teaching Activity Collection > MnSTEP Activities > Balanced Forces

Balanced Forces

Rashelle Hoffmann
E.C.H.O. Charter School
Based on Holt Science and Technology
Forces, Motion, and Energy Ch. 1 Sect. 2
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In this lesson the students will learn the scientific definition of force. The students will see different examples of forces on an object and will gain an understanding that there are at least two forces acting on an object at all times. The students will use the newly learned information to create a poster that shows an example of balanced forces. The poster should show the forces acting on the object. As a step further the students could also show the forces acting on the object if the forces become unbalanced.

Learning Goals

Learning Goals
1. The students will gain a scientific understanding of force.
2. The students will understand how different forces act on an object.
3. The students will use their new understanding to develop models of force on an object.
Key Concepts
1. All objects have at least two forces acting upon them.
2. Balanced forces will not cause a change in the motion of a moving object.
3. Balanced forces will not cause a non moving object to start moving.
Key Vocabulary
1. Net Forces
2. Balanced Forces
3. Unbalanced Forces

Context for Use

This activity is for use in a middle level classroom with students gaining an understanding of forces acting on objects. The class size can vary;, if large, complete the activity in groups. The lesson is mostly lecture with many examples and drawing activities to summarize. This is considered an alternative assessment activity in the Holt Short Courses. This activity is a great tool for the students that are visual learners.

Subject: Physics:Classical Mechanics
Resource Type: Activities:Classroom Activity
Grade Level: Middle (6-8)

Description and Teaching Materials

Holt Science and Technology "Forces, Motion, and Energy:2007
The students will take notes on forces, the difference between balanced and unbalanced forces, and forces acting on objects. During the lecture and note-taking the concepts will be emphasized with examples, both from the book and real-life situations. (one student pushing a desk, tug of war, etc.) For the activity each student or each group will need a poster sized piece of paper and drawing materials. The students will make a poster that shows an example of balanced forces (elevator at rest, gymnast motionless on the balance beam). The poster should show the forces acting on the object and as an extension, what happens to the object if the forces become unbalanced. (Page 12 of book stated above) As a closure to this lesson, each student and/or group will explain the forces acting on their object to the class.

Teaching Notes and Tips

In this section of the Holt Science and Technology book, the students have not covered gravity or friction as forces yet; these are found in following chapters. You may choose to wait with this activity if you want the students to include specific forces. What you are looking for in the posters is to see if the students have achieved an understanding of balanced and unbalanced forces.
I have had some students struggle with this activity mostly because of the drawing part of it but not the concept part. For some students that struggle or feel a frustration with drawing, I will provide magazine/clipart for the students to glue on their paper, so they only need to discuss where the arrows (forces) would go.


The students will be assessed on the concepts by showing directionality of force on an object and the difference between the balanced and unbalanced forces.


6.II.E - Forces of Nature- The students will understand that a variety of forces govern the structure and motion of objects in the universe.

References and Resources