Investigating Contact Forces

Overview

In this second lesson of the unit “Fast Forces: Play and Learn”, students investigate contact forces using a “Table Tennis Tap” activity. They will plan, run a short, fair test, record observations in a table, and begin to compare results to notice patterns.

Learning intentions

• Students will investigate contact forces using the Table Tennis Tap activity.
• Students will collect and record observations and measurements during a fair test.
• Students will compare their results with expected outcomes and use simple evidence to describe patterns.

Success criteria

• I can set up the experiment safely and follow the steps.
• I can record results clearly in a table (including my measurements).
• I can describe what happened and identify a simple pattern in the results.
• I can explain what I changed and what I kept the same to make the test fair.

Key vocabulary

contact force, push, tap, friction, distance, fair test, variable, record, observation, measurement, pattern, evidence, conclude

Curriculum links

• Science: AC9S3I02 use provided scaffolds to plan and conduct investigations, including identifying elements of fair tests and safe equipment use.
• Science: AC9S3I03 follow procedures to make and record observations, including formal measurements using familiar scaled instruments and digital tools as appropriate.
• Science: AC9S3I04 construct and use representations, including tables, to organise data and identify patterns.
• Science: AC9S3I05 compare findings with others, consider if investigations were fair, identify questions for further investigation and draw conclusions.
• Science: AC9S3I06 write and create texts to communicate findings and ideas using scientific vocabulary.

Lesson structure (60 minutes)

1. 0–5 min · Hook (demo + question). Teacher taps a ball lightly and then harder (or uses two known strengths) and asks: “What changed when I tapped the ball?” Students share quick ideas in pairs.

2. 5–12 min · Safety + setup review. Teacher checks equipment, demonstrates the correct tap technique, and reminds students about staying behind the marked line and handling balls safely. Students listen and repeat the key steps: set distance markers, place the ramp/panel as shown, and start the timer/recording (as required).

3. 12–20 min · Fair test planning (scaffolded). Teacher displays the class fair-test checklist: what to change (tap strength or surface), what to keep the same (starting position, angle/height, ball type), and what to measure (distance travelled from the tap line). Students complete a quick planning box on the activity sheet using sentence starters: “We will change… We will keep the same… We will measure…”

4. 20–35 min · Investigation run (Table Tennis Tap). Students work in small groups (or teacher-led rotations). Each group performs the agreed fair test for 3 trials. Teacher circulates to check correct recording and consistent starting position. Students record each trial’s distance (or other agreed measurement) in the table and write one sentence observation for each trial.

5. 35–45 min · Represent data (table check + pattern hunt). Teacher models how to read the table and look for a pattern (e.g., “When tap strength increased, distance increased”). Students highlight the biggest distance and smallest distance and circle any repeated results.

6. 45–52 min · Compare findings with others. Teacher facilitates a short whole-class sharing: each group reports their average distance (or their trend) and one fairness check (“Was our test fair? What might have changed?”). Students listen, then add a comparison note: “Our results were similar/different because…”

7. 52–60 min · Conclusion writing (mini-scientist report). Students complete the “Draw a conclusion” section using provided frames:

• “Our investigation showed…”
• “This is supported by our evidence…”
• “The test was fair because…”
• “Next we could investigate…” Teacher collects sheets for marking.

Resources

• Table Tennis Tap activity materials (ramp/panel, table marker line, balls, measuring tape or scaled ruler)
• Student investigation sheets with table for 3 trials
• Fair test checklist (change/keep same/measure)
• Clipboards or hard backing boards
• Timer (if used) and/or teacher-provided recording prompts
• Safety instructions card (eyes on equipment, stand behind line)
• Coloured pencils/highlighters
• Optional: phone/tablet for quick photo of setup (only if school policy allows)

Assessment

• Formative: teacher observations during setup and trials (correct procedure, safe behaviour, consistent starting position).
• Formative: check students’ tables for completed trials and accurate recording of measurements.
• Summative-for-today: short conclusion paragraph using the sentence frames; ability to identify a pattern and mention fairness.

Differentiation

• Support: provide extra sentence starters for “variable / kept the same / measurement” and offer a model completed table.
• Support: group students strategically so at least one student can act as “Recorder” and one as “Time/Measure” (reduce cognitive load).
• Extension: ask students to propose an improved fairness method (e.g., “How could we make tap strength more consistent?”) and predict the outcome of that change.
• EAL/SEN: allow non-verbal evidence (circle the trend, label “more/less distance”) before writing; offer a word bank for contact force terms.

Answer key / teacher notes (quick)

• Expected pattern (typical): stronger taps/contact force lead to greater distance; lighter taps lead to shorter distance.
• Fair test elements to look for in student responses:
• Change only one factor (e.g., tap strength) per run.
• Keep starting position and surface conditions the same.
• Measure the same way each trial (from tap line to stopping point).
• Common issues to check:
• Inconsistent starting position.
• Measuring from the wrong reference point.
• Not repeating trials (or missing a value).