A hands-on physical science and experimental design lesson where students investigate how ramp height influences marble speed using a stopwatch. Students develop testable questions, formulate hypotheses, identify independent, dependent, and controlled variables, and practice fair testing through guided trials.
Hold marble at top of ramp. Timer gets stopwatch ready at 0.00s.
3
Finger-Release Drop
Count "3-2-1 release!" Start timer simultaneously. NO pushing!
4
Measure Speed / Time
Stop stopwatch when marble hits the bottom. Record seconds; do 3 trials!
Remember: Faster speed = fewer seconds on the stopwatch!
Lab Debrief: Speed Findings
Scientific Synthesis
Claim
How did increasing ramp height change the marble's speed? State your claim clearly.
Evidence
Quote your stopwatch speed data: "At 1 book the average time was ___ s, but at 4 books it dropped to ___ s (much faster speed!)."
Fair Test
Why would delayed timing or pushing ruin our speed comparison? (It introduces uncontrolled human variables!)
Complete your Part 7 reflection and shaded comparison bars before turning in!
Medium: 2 Books (2 stacked)
High: 4 Books (4 stacked)
6
Visual Comparison (Label Scale & Shade Average Seconds)
Key: Less Time = Greater Speed!
Write your time values on the scale lines below, then shade each bar to represent your average seconds:
1 Book:
2 Books:
4 Books:
Seconds:
7
Scientific Analysis & Conclusions
1. Claim: What was the relationship between ramp height and the marble's speed down the ramp?
2. Evidence: Support your claim using exact stopwatch times from your data table (compare 1 book to 4 books):
3. Fair Test Reflection: If the timer started the stopwatch too late or someone pushed the marble, why would that ruin the experiment?
Ramp Runners • Student Investigation Guide Page 2 of 2
3. Push Reflex: Ensure launchers release smoothly from fingertips without adding an initial push or shove down the ramp.
Ramp Runners • Teacher Answer Guidance Page 1 of 2
Benchmark Data & Scientific Analysis Key
Typical classroom stopwatch timing ranges and rubric scoring criteria.
Lab Parts 5 – 7
Typical Classroom Data Range (Standard Ramp Track)
Ramp Height
Trial 1 (s)
Trial 2 (s)
Trial 3 (s)
Expected Typical Time
1 Book (low)
3.12 s
3.05 s
3.19 s
2.8 – 3.4 s
2 Books (med)
1.84 s
1.91 s
1.77 s
1.6 – 2.1 s
4 Books (high)
1.02 s
0.98 s
1.06 s
0.9 – 1.3 s
Physics Key: Higher ramps convert more gravitational potential energy into kinetic energy, producing faster acceleration and shorter transit times down the ramp.
Part 7: Model Reflection Responses
1. Claim Exemplar:
"Increasing the height of the ramp caused the marble to roll with significantly greater speed, resulting in fewer seconds to reach the bottom."
2. Evidence Exemplar:
"At 1 book, the marble took an average of 3.12 seconds to complete the ramp. When raised to 4 books, the average time dropped to 1.02 seconds, completing the ramp 2.10 seconds faster (roughly three times the speed)."
3. Fair Test Reflection Exemplar:
"Starting the timer late or pushing the marble introduces an uncontrolled variable. If someone pushes, we don't know whether the faster speed came from the steeper ramp or the hand force. Fair testing requires locking every factor except ramp height."
Formative Assessment Rubric (4-Point Scale)
Category
4 - Exemplary
3 - Proficient
2 - Developing
1 - Beginning
Variables (Parts 1-3)
Independently creates testable speed question, If/Then hypothesis, and accurately identifies IV, DV, and 3 CVs.
Creates question and hypothesis; identifies IV and DV; names at least 2 CVs.
Confuses IV and DV or leaves controlled variables blank.
Incomplete variable identification; question is not measurable.
Data & Trials (Parts 5-7)
All 9 stopwatch trials recorded in seconds (s); calculated averages and shaded bars accurately reflect times.
All 9 trials filled; minor calculation error in averages; shaded graph present.
Missing multiple trials or units omitted; graph incomplete.
Single trial per height; no averages; messy data.
Reflection (Part 7)
Clear claim on speed/time, exact seconds cited as evidence, articulate fair test reflection on timing and pushing.
Clear claim with stopwatch times mentioned; explains why pushing or timing errors ruin fair testing.
Claim made without data evidence; vague reflection on timing/pushing.
Off-topic claim; no stopwatch evidence provided.
Ramp Runners • Teacher Answer Guidance Page 2 of 2
How to Calculate the Average Time:
Add the 3 trial times together, then divide by 3: (Trial 1 + Trial 2 + Trial 3) ÷ 3 = Average
Unit: Seconds (s)
Ramp Height (IV)
Trial 1 (s)
Trial 2 (s)
Trial 3 (s)
Calculate Average (s)
1 Book (Low Ramp)
3.20 s
3.00 s
3.10 s
2 Books (Medium Ramp)
1.90 s
1.80 s
2.00 s
|
| 4 Books (High Ramp) | 1.05 s | 0.95 s | 1.00 s |
|
5
Visual Comparison (Graph Your Averages)
Fewer Seconds = Faster Marble
Each block on the graph represents 0.5 seconds. Shade the blocks horizontally to match your calculated average transit time for each ramp height:
1 Book:
2 Books:
4 Books:
Time (s):
0.0s 0.5s 1.0s 1.5s 2.0s 2.5s 3.0s 3.5s 4.0s
6
Independent Scientific Analysis (CER)
1. Scientific Claim: What exact relationship did you observe between ramp height and the marble's roll time / speed?
2. Data Evidence: Cite your exact calculated average times from the table comparing 1 book to 4 books to prove your claim:
3. Fair Test Evaluation: If a student accidentally pushed the marble at the top instead of letting go with a clean release, how would that invalidate the test results?
Ramp Runners • Independent Makeup Assignment Page 2 of 2
