Free / Grades 4-6, with reading and number support
Falling Paper Lab
How can we explain a difference in falling time without claiming more than our evidence shows?
4 flexible sessions / about 140 minutes including practice / science, math, reading and art
Suggested rhythm: two sessions a week for two weeks. Week 1: plan and calculate. Week 2: compare repeated trials and explain. Pause or spread sessions out as needed.
Reading, watching and paper activities are free. Parents and instructors can save a collection; scheduling it for a student requires Plus or Lifetime. No upload is required.
Before you begin
Compare decimal numbers, subtract and divide with support, and distinguish a prediction from an observation. A calculator, pointing or an adult reading aloud is welcome. The linked lessons introduce air resistance and average speed.
A desk-based investigation. Use the invented records below; no dropping experiment is required. Do not drop devices or heavy objects, climb furniture, lean from windows or build a vacuum container. These sample times are not measurements you made. Keep any separate real observations clearly labeled.
Materials
- 4 sheets per learner: Investigation journal
Print four pages or copy their headings into a notebook.
- 1 sheet per learner: Evidence poster
Use the blank side of clean paper or explain the same sections aloud.
- 1 per learner: Pencil
Point, dictate or use an accessible writing tool.
- 1 shared, optional: Calculator
Work through the decimal calculations with an adult.
- 1 shared: Browser with audio or transcripts
Read the existing transcripts together. Separate worksheet printing is optional.
Choose the support that fits
- More support: compare the shortest and longest times first. An adult can calculate while the learner selects the values and explains their meaning.
- More challenge: explain why distance divided by mean time is not generally the mean of the separate trial speeds. Do not label either number as the final falling speed.
- Access options: describe a diagram, point to table cells or dictate your explanation. No outdoor activity, recording, upload or public presentation is needed.
What good evidence looks like
- Name the changed feature and at least three conditions to keep alike.
- Calculate average speed with distance and time units, without calling it final speed.
- Use all three trials for each shape; keep the invented-data label.
- Separate the sample result, a possible explanation and a limit of the evidence.
- Keep an initial explanation, revise it and present a labeled evidence poster privately.
These are discussion criteria, not a new automatic score. Existing lesson and worksheet records keep their own subjects. Checking off a planned task does not demonstrate mastery or add a second grade.
Session 1 / about 35 minutes
Change one feature, keep a fair comparison
Goal: Plan a shape comparison that does not also change the starting distance or amount of paper.
Preparation / about 5 minutes of adult support: Have journal 1 ready. Use the supplied drawings and records; no physical drop is needed. Start a first explanation that you will revisit in session 4.
Gravity pulls both shapes downward. Air can resist their motion. Crumpling a sheet changes its shape without adding paper. To investigate shape, compare equal sheets and the same starting distance, release method and indoor air conditions. A flat sheet released higher than the ball would change two features. Even a careful comparison needs repeated trials. A prediction is what you expect before looking at the results.
A pretend researcher changes the shape and turns on a fan. Ask what could explain a changed time. How would keeping the air conditions alike improve that comparison?
- Falling objects and air resistance / about 5 minutes
- Gravity and Falling Paper / about 10 minutes
- Plan the paper comparison / about 20 minutes
Fun fact: Shape can change drag even when the amount of material has not changed. Shape is not the same quantity as mass. Source
S3U / Falling Paper Lab / Journal 1 of 4
One change, several controls
Pretend setup: equal sheets of the same paper, one flat and one crumpled, released without a push through a vertical distance of 0.60 m in still indoor air. Keep this setup for the later invented records.
| Feature | Change or keep alike? Why? |
|---|---|
| Paper shape | |
| Amount and type of paper | |
| Starting distance and release method | |
| Air conditions |
My prediction before reading the times, and a possible reason:
Which unfair comparison would make my explanation less convincing?
Session 2 / about 35 minutes
A time is not a speed
Goal: Calculate an average speed and distinguish it from a final or constant speed.
Preparation / about 5 minutes of adult support: Have journal 2 and a calculator if useful. Read m as meters, s as seconds and m/s as meters per second. Decimals can be calculated together.
For a straight downward trip, average speed is distance divided by elapsed time. A worked example is 0.60 m divided by 0.40 s, which is 1.50 m/s. This describes the whole trip, not the speed at its last instant. For the same distance, a longer time means a smaller average speed. Use the exact invented values in the journal to practice; their neat numbers do not make real measurements exact.
Ask whether an average of 1.50 m/s proves the object moved at 1.50 m/s at every instant. What extra observations would you need to know how the speed changed?
- Time a fall and compare fairly / about 5 minutes
- Falling Speeds: Measure Average Speed / about 10 minutes
- Compare two invented trips / about 20 minutes
Fun fact: A falling object can keep moving even when opposing forces balance. Constant speed means no speed change, not no motion. Source
S3U / Falling Paper Lab / Journal 2 of 4
Distance divided by time
Independent invented example: flat paper travels straight down 0.60 m in 1.20 s; crumpled paper travels 0.60 m in 0.40 s. Calculate average speed, not final speed. These are not observations you made.
| Shape / distance | Elapsed time (s) | Average speed (m/s) |
|---|---|---|
| Flat / 0.60 m | 1.20 | |
| Crumpled / 0.60 m | 0.40 |
Which trip has the greater average speed? Use both distance and time in your explanation.
Why can these two whole-trip numbers not tell us the speed at the last instant?
Session 3 / about 35 minutes
Keep every trial, not just the favorite
Goal: Compare repeated times and explain a limit that repetition does not remove.
Preparation / about 7 minutes of adult support: Bring journals 1 and 2. Copy all six invented times into your comparison; do not quietly discard a value because it differs from your prediction.
Repeating a measurement can reveal variation. For a mean, add all the times and divide by the number of trials. For a range, subtract the smallest time from the largest. A separate example of 0.42, 0.38 and 0.40 s has mean 0.40 s and range 0.04 s. Repetition does not fix every problem: consistently using the wrong starting distance could affect every trial. Keep units and describe limits instead of calling an average the exact truth.
Ask why choosing only the quickest flat trial and slowest crumpled trial could hide useful evidence. A suspicious record should be labeled and investigated, not secretly removed.
- Summarize all the trial times / about 15 minutes
- Read an overconfident claim / about 10 minutes
- Explain a better next comparison / about 10 minutes
Fun fact: Measurement uncertainty can have several sources. Variation across repeated readings is useful evidence, but it is not the only source to consider. Source
S3U / Falling Paper Lab / Journal 3 of 4
Repeated records and their limits
Invented trials, all over 0.60 m with the session 1 setup. Flat times: 1.10, 1.20, 1.30 s. Crumpled times: 0.38, 0.40, 0.42 s. Means and ranges summarize these examples only.
| Shape | Mean time (s) | Range (s) |
|---|---|---|
| Flat | ||
| Crumpled |
Use all three times per shape. Show your addition and subtraction, then compare the two sets.
Rewrite "Crumpled paper always falls exactly three times faster." What can these records support, and what can they not establish?
Session 4 / about 35 minutes
Build an explanation that earns its claim
Goal: Present a revised claim, evidence and limitation without confusing a model with a measurement.
Preparation / about 8 minutes of adult support: Bring the first explanation, all journals and one poster sheet. An adult may listen or read; the learner can also rehearse privately. Nobody is monitoring live.
Your poster needs a question, setup, all trial times, a careful claim and a limitation. An explanation about air resistance connects the results to a model; the table alone does not measure drag. In a no-air model, objects released from rest at the same height in the same gravitational field have the same falling acceleration, regardless of their masses. That is a different situation from our invented in-air records. Revise your first explanation rather than hiding it.
Ask which sentence reports the supplied data and which explains it. Then ask what would have to be checked before making a claim about all paper shapes or every real drop.
- Design an evidence poster / about 15 minutes
- Present and revise the explanation / about 15 minutes
- Choose the next question / about 5 minutes
Fun fact: Removing air changes the model: drag is absent, but gravity still acts. A vacuum is not the same as a place without gravity. Source
S3U / Falling Paper Lab / Journal 4 of 4
My claim, evidence and limit
Use the invented records, not invented personal experience. Present on paper, aloud or by pointing. Keep your first explanation and make a revised one; no upload or public presentation is needed.
| Poster section | What evidence belongs here? |
|---|---|
| Question and fair setup | |
| All trial times with units | |
| Claim and possible explanation | |
| Limit and next question |
What did I change in my first explanation, and which evidence made me reconsider?
What question did I receive or ask myself? How would I investigate it fairly?
What changed in your explanation?
Show your evidence, explain one revision, and choose a question to investigate next. You can keep everything on paper.
Optional: record actual offline learning in Learning Records. Keep reported minutes separate from website time. For an assigned pack, use your existing daily tasks; this page does not award additional completion credit.