Unit 22 - Robots
Robots
General Learning Objectives
At the end of the lesson, the students are expected to:- understand the concept of action and reaction forces and how they affect the movement and stopping of objects
- apply their understanding by measuring time and observing how the height of a ramp influences movement
- use engineering and art skills to create simple machines (e.g., bristle bots and artbots) to demonstrate action and reaction forces
Activity 1: Action Reaction!
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Objective:
Students will understand the concept of action and reaction forces, as well as how objects move and stop.
Materials Needed:
- Toy cars or small balls
- Ramp (can be a board or a book)
- Stopwatch
- Meter stick or measuring tape
- Objects of different weights (e.g., small blocks)
- Worksheet for calculations
- Place the toy car on a ramp and release it.
- Observe how the car accelerates and moves down the ramp.
- Ask students: “What causes the car to move?” (Gravity pulls it down.)
- Place an obstacle (e.g., a small block) at the end of the ramp.
- Ask: “What happens when the car hits the obstacle?” (The car stops because of the reaction force from the obstacle.)
- Discuss how friction and other forces act on moving objects.
- What happens when you push something?
- Why do some objects move faster or slower on different surfaces?
- Why does the car stop when it hits the obstacle?
Activity 2: Measuring Time and Comparing Heights
Objective:
Students will measure the time it takes for a toy car to travel down a ramp and observe how changing the height of the ramp affects the car’s movement.
Materials Needed:
- Toy cars
- Ramp (can use books or blocks to create different heights)
- Stopwatch or timer
- Measuring tape or ruler
- Data recording sheet***
- Set up the ramp at a low height (e.g., using one book).
- Measure the height of the ramp and note it on the data recording sheet.
- Release the toy car from the top of the ramp and measure the time it takes to reach the bottom.
- Record the time on the sheet.
- Increase the height of the ramp by adding more books or blocks.
- Measure and record the new height and the time it takes for the car to reach the bottom again.
- Repeat the experiment with at least three different heights.
- Have students compare the times recorded and answer questions like: “What happened to the time as we increased the height of the ramp?” “Why do you think the car moved faster/slower?”
- Help students create a bar graph showing the height of the ramp on the x-axis and the time taken on the y-axis.
- Does a higher ramp make the car move faster or slower? Why?
- What can we conclude about the effect of ramp height on the car’s movement?
Activity 3: Push that ball! (Physical education)
Objective:
Students will experience action and reaction forces through physical activities.
Materials Needed:
- Balls of various sizes
- Cones or markers
- Stopwatch
- Set up a small relay race where students must push a ball to a marker and back.
- Add variations: some balls may be heavier or lighter, or students can use different parts of their body to push (hands, feet, etc.).
- What makes some balls easier or harder to push?
- Why do some balls stop sooner than others?
Activity 4: Building Bristle Bots (Engineering)
Objective:
Students will build simple bristle bots and experiment with action and reaction forces.
Materials Needed:
- Toothbrush heads
- Small vibrating motors (like those in electric toothbrushes)
- Coin cell batteries
- Tape or glue
- Markers for decoration
- Organize a bristle bot duel! Create a small arena and let the bristle bots compete to see which one stays inside the arena the longest.
Activity 5: Building Artbots (Art and Engineering)
Objective:
Students will create artbots to see how action and reaction forces can be used creatively.
Materials Needed:
- Plastic cups or small containers
- Small motors
- Markers or crayons
- Tape or glue
- Paper
Activity 6: Rope Pull
Rope Pull – Exploring Force Through Cooperative Movement
In this activity, teams of three to five students play a relay by sitting on a low board, and one by one take turns to pull a rope attached to a fixed point to move themselves from start to finish. This game naturally illustrates key physics concepts in action: force magnitude (how hard they pull), direction and sense (the angle of the pull and how it aligns with the movement), and team coordination (how effort is shared among group members).
Additionally, students can try the same activity by trying to play the whole team at the same time over a bigger board; here, communication and coordination will play a role aside from just strength! As students participate, teachers can guide them to observe and reflect on:
- How combined force affects motion: When students pull together in a coordinated way, the board moves more smoothly and quickly than when efforts are unbalanced.
- Body mechanics and force application: Students can experiment with different postures or hand positions to see how their individual pulling force contributes to team performance.
- Teamwork and strategy: Because this activity relies on shared effort, teachers can help students discuss how communication and synchronization influence results.
- Real-world connections: Use the game to connect to everyday applications of force, such as tug-of-war, rowing teams, rescue scenarios, or machines that rely on rope and pulley systems.
Activity 7: Land Mines
Land Mines – Forces, Balance, and Movement
In this full-body, cooperative activity, students enter a clearly marked circular arena scattered with small pins representing “mines.” Working in pairs, each student holds a stick and moves carefully within the space, aiming to avoid knocking the pins over. The activity requires coordination, balance, communication, and strategic control of movement.This game provides a meaningful way to explore forces and balance through experience. As students push or pull using the stick, they can feel how applying force in one direction creates a response in the opposite direction. This idea relates to Newton’s Third Law, often described simply as: every action has a reaction. Students experience this when they push against the stick, their partner, or the ground and feel their own body being pushed back. To stay upright and avoid falling, students must constantly make small balancing movements. These include adjusting their feet, bending their knees, shifting their weight, and tightening their core. Each push or pull changes how their body is balanced, and the body responds by making quick adjustments to stay stable. This helps students understand that balance is not static, but something the body continuously controls in response to forces.Teachers can support learning by guiding students to notice:
- How pushing or pulling harder or in a different direction changes movement
- How balance depends on body position and weight distribution, not only strength
- How small changes in posture or grip can prevent losing balance or disturbing the “mines.”
Through this activity, students explore important science ideas related to forces, movement, and balance in a concrete and engaging way. The experience builds a foundation for later physics learning while remaining accessible and meaningful at this stage.
STEPAM Components
- Science - Understanding action and reaction forces and their effects on moving and stopping objects
- Technology – Exploring how motors work and using them in hands-on projects (e.g., bristle bots and artbots)
- Engineering – Building simple machines, like bristle bots, to explore movement and force
- Physical Education – Push that Ball relay race, where students apply action and reaction concepts by pushing different types of ball
- Art – Creating artbots that draw patterns, showing how forces can create art
- Mathematics – Measuring and recording the time and height data of moving objects; creating graphs to represent and interpret this data.
