Calculating Net Force Lesson Plan (TEKS 6.7B): A Complete 5E Lesson for Balanced and Unbalanced Forces

Inside the Calculating Net Force 5E Lesson

The 5E instructional model walks students through five phases: Engage, Explore, Explain, Elaborate, and Evaluate. It flips the traditional lecture-first sequence on its head. Students explore a concept hands-on before you ever explain it, which means by the time you do explain it, they have something to hook the vocabulary onto.

I switched to the 5E model years ago and stopped going back. Kids retain more, ask better questions, and stop staring at me waiting to be told the answer. The Calculating Net Force 5E Lesson is built on this framework from start to finish. Here's how it plays out across the five phases.

🎯 Engage

Day one is the rope-pull demonstration. The teacher stages three rounds of tug-of-war right in the classroom. Round one is two students of roughly equal strength on opposite ends of a rope. Round two adds a third student to one side. Round three is the teacher's choice (sometimes a teacher joins the smaller side, sometimes a single student takes on three).

For each round, students fill in a prediction on their student sheet, watch what happens, and then sketch the force arrows they observed. By the end of the period, kids have three diagrams in their own handwriting, three real-world predictions they can compare against what actually happened, and a working definition of balanced and unbalanced forces in their own words. Nobody has heard the term "net force" yet. That's the point.

What's included in the Engage:

• Teacher directions for the three-round rope-pull demonstration
• Printable student prediction and observation sheet
• Answer key with the expected outcomes and discussion questions
• Four learning objective slides (standard verbatim, "Calculate the net force" highlighted, "I CAN...", and "WE WILL...")
• An illustrated Force and Motion Word Wall in English and Spanish covering the full unit vocabulary

🔬 Explore

The Calculating Net Force Station Lab is the heart of the Explore phase. Students rotate through 8 stations (plus a 9th challenge station for early finishers) over one class period. The Station Lab is split into four input stations (where kids take in new information) and four output stations (where they show what they learned).

The four input stations:

• 🎬 Watch It! — Students watch a short video on balanced and unbalanced forces and answer guided questions.
• 📖 Read It! — A one-page reading passage at two differentiated levels, with a Spanish version included.
• 🔬 Explore It! — The hands-on net force task (the heart of the Station Lab) where students use spring scales, small blocks, and a flat surface to pull objects in opposite directions and read the net force right off the scale.
• 💻 Research It! — Reference cards with sample free-body diagrams, the rule for combining forces in the same vs. opposite directions, and the unit "N" (Newton).

The four output stations:

• 📋 Organize It! — A card sort where students physically place 12 force diagrams under the right category (balanced or unbalanced) and the right net force value.
• 🎨 Illustrate It! — Students draw free-body diagrams for three given scenarios (tug-of-war, sliding box, book at rest) and label the net force.
• ✍️ Write It! — Three open-ended questions in complete sentences (this is where you see who really gets it).
• 📝 Assess It! — A short formative check with multiple choice and a fill-in-the-blank vocabulary paragraph.

Print and digital versions are both included. If you want the full breakdown of what happens at every single station, what students produce, and how to set it up, that's in our dedicated Station Lab post.

→ Read the full Calculating Net Force Station Lab walkthrough 8 stations, materials list, teacher tips

The Station Lab is included in the full 5E lesson. You don't need to buy it separately if you're getting the whole unit.

📚 Explain

Here's the real payoff of doing the Engage and Explore before the Explain: by the time kids hit this phase, they've already felt balanced and unbalanced forces with a rope and read net force right off a spring scale. They have a working understanding before you ever start naming things formally. The discussions get deeper, the questions get sharper, and you spend less time defining and more time pushing their thinking.

The Calculating Net Force Presentation walks 6th graders through the full scope of TEKS 6.7B one concept at a time, with arrow diagrams on nearly every slide. The deck opens with the big idea (the net force is the total force acting on an object after all of the individual forces are combined), and then builds out the two scenarios that drive every diagram in the rest of the unit: forces in the same direction add, and forces in opposite directions subtract.

Students learn that when the net force on an object is zero, the forces are balanced. The object's motion does not change. A book sitting on a desk has gravity pulling it down and the desk pushing up with equal strength, so the net force is zero and the book stays still. The deck pauses here to flip the textbook example on its head: a car cruising at a steady 60 mph down a straight road also has balanced forces, even though it's moving. The engine pushes forward, friction and air resistance push back, and those forces are equal. Because the net force is zero, the speed doesn't change. Balanced means motion doesn't change, not that there is no motion. That subtle distinction trips up a lot of 6th graders, so the deck lingers there with a built-in Think About It prompt.

The other half of the unit covers unbalanced forces. When the net force is not zero, the forces are unbalanced and the object's motion changes. That change could be speeding up, slowing down, or changing direction. The phrasing students need to walk away with is that unbalanced forces cause changes in motion, not that they "cause motion." The deck includes a built-in calculation sequence where students work through six free-body diagrams in order: two with same-direction arrows (10 N + 15 N right, etc.), two with opposite-direction arrows (20 N right vs. 10 N left), and two with vertical arrows (gravity vs. normal force on a box at rest, gravity vs. lift on a rising rocket). For each, students write the net force value and the direction. By the end, they're not adding random numbers. They're tracking arrows.

For every scenario, students see three model types: a real-world photo, a free-body diagram with arrows and numbers, and a one-sentence prediction of what happens to the object's motion. That repetition (different scenarios, same three model types) is what bakes the calculate the net force verb of TEKS 6.7B into long-term memory.

What makes the Calculating Net Force Presentation different from a typical physics slideshow is that kids are doing something on almost every single slide. It's not a lecture deck. It's a participation deck. "Your answer:" prompts appear on most slides, Brain Breaks reset attention every few slides, Quick Action INB tasks (the balanced vs. unbalanced sort, a "draw the missing arrow" activity, a six-step net force calculation sequence) show up throughout, and Think About It prompts push deeper into bigger ideas like "Can balanced forces ever describe something that's moving?" and "What happens to a rocket when the lift force becomes bigger than gravity?" The deck closes with a Check for Understanding tied back to the Essential Question: How do I calculate the net force on an object and decide whether the forces on it are balanced or unbalanced?

The Explain materials in this product include:

• An editable 36-slide Presentation at two differentiated levels (Dependent and Modified), works in PowerPoint or Google Slides
• A guided fill-in-the-blank student notes handout that mirrors the Presentation, with answer key
• A Paper Interactive Notebook (English and Spanish) students cut, fold, and glue into their notebooks
• A Digital Interactive Notebook at both levels with answer keys, for 1:1 classrooms or Google Classroom

The Explain runs across two class periods. The built-in Think About It prompts are where the real discussion happens, so let those breathe.

🛠️ Elaborate

The Elaborate phase is where students stretch what they learned about net force, balanced, and unbalanced forces and put it into a project of their choosing. In this 6th grade physics lesson, that's a Student Choice Project board with six different project options plus a "design your own" pathway.

Students might design an illustrated story where every page is a different free-body diagram and a net force calculation, build a small cardboard tug-of-war scene with labeled force arrows and a written explanation, or record a video where they walk the camera through three real-life scenarios (a book at rest, a soccer ball getting kicked, a car braking at a stoplight) and calculate the net force for each. There are options for kids who love to write, kids who love to draw, kids who love to build, and kids who love to perform. Whatever the project, the point is the same: students apply net force calculations to a real-world artifact instead of a worksheet.

Choice is the whole point. By letting students pick how they show their thinking, you get more authentic work for TEKS 6.7B and you actually get to see what they understand about balanced and unbalanced forces.

The rubric (the part teachers actually want)

Every project, no matter which option a student picks, is graded on the same rubric. Five categories at 20 points each:

• Vocabulary (20 pts) — At least four words from the lesson are used in context.
• Concepts (20 pts) — At least two key concepts from the lesson are referenced.
• Presentation (20 pts) — The project grabs attention and is well-organized.
• Clarity (20 pts) — Easy to understand. Free of typos.
• Accuracy (20 pts) — Force arrows and net force values are correct. The science is right.

The rubric uses a minus / check / plus shorthand on every row so you can grade a stack of projects quickly without re-reading every criterion.

Two differentiated versions in one file

The standard version is for students ready for independent application of net force calculations. The Reinforcement version is for students who need additional vocabulary or concept support. Three of the six options are swapped for projects with a tighter vocabulary tie-in, and "design your own" is replaced with "collaborate with the teacher" so kids aren't pitching cold.

✅ Evaluate

The Evaluate phase wraps the unit with a formal assessment. It's not all bubble-in. Several questions hand students a set of free-body diagrams and ask them to circle the balanced one (or write the net force value) and then describe why.

The full assessment has 12 questions across five formats:

• Multiple choice (4 questions) covering the definition of net force, balanced vs. unbalanced, units (Newtons), and what happens to motion in each case
• Hotspot / visual (2 questions) where students circle the free-body diagram that shows balanced forces and describe the difference between two diagrams
• Multiselect (2 questions) where students pick all the diagrams that result in a non-zero net force
• Short answer (2 questions) on why a moving car can still have balanced forces, and on how to find the net force when two arrows point in opposite directions
• Multipart scenario (2 questions) with a 3-student classroom debate where kids identify which net force calculation is correct and which diagram supports it

A modified version is included for students who need additional support. Fewer multiple-choice distractors and sentence-starter scaffolds on the short-answer items.

If you've taught all five phases, this assessment shouldn't surprise anyone. It's a chance for kids to show you they get it.