Motion Data Quality Concept Check
A focused O-Level concept check on collecting, plotting and interpreting motion data with honest measurement limitations.
Learning goals
- Work through the questions and use the feedback to plan revision.
Learning objectives
- State what speed means
- State what velocity means, including its direction
- Calculate average speed from total distance and total time
- Calculate acceleration as change in velocity divided by time taken
- State what uniform acceleration means
- Interpret examples of non-uniform acceleration
- Plot and interpret displacement–time and velocity–time graphs in one dimension
- Deduce rest and uniform or non-uniform velocity from a displacement–time graph
- Deduce rest, uniform velocity and uniform or non-uniform acceleration from a velocity–time graph
- Use signed area under a velocity–time graph to determine displacement
- Recall constant free-fall acceleration near Earth as approximately 10 m/s²
This four-question check targets repeatability, instrument resolution, anomalous data and experimental limitations. Choose an answer before opening its reasoning.
1. Reliable motion trends
A trolley’s position is recorded every 0.20 s. Which action most improves the reliability of the plotted motion trend?
- A. Repeat the run and compare or average corresponding readings
- B. Add decimal places not supported by the ruler
- C. Remove every point away from a perfect line
- D. Change the time interval after each reading
Check answer and reasoning
A. Repeated trials expose random variation and allow corresponding readings to be compared. Extra unsupported digits do not improve a measurement.
2. Recording precision
The position scale can be read to the nearest 1 mm. How should a reading near 84 mm normally be recorded?
- A. 84 mm
- B. 84.0000 mm
- C. About 80 mm only
- D. Exactly 84.237 mm
Check answer and reasoning
A. Record 84 mm. The precision should match the scale resolution rather than imply unavailable certainty.
3. An anomalous point
One point lies away from an otherwise smooth position–time trend. What is the best first response?
- A. Check the original observation and method before deciding whether it is anomalous
- B. Delete it automatically
- C. Move it onto the line
- D. Draw the graph through every point in sequence
Check answer and reasoning
A. Check the observation and method first. A point needs an evidence-based reason to be treated as anomalous; it must not be moved or discarded merely to improve the graph.
4. Honest limitations
Which statement is an honest limitation of a hand-timed trolley experiment?
- A. Reaction time affects the start and stop times
- B. The trolley has one exact speed throughout every run
- C. A smooth graph proves there is no uncertainty
- D. Repeating removes all systematic error
Check answer and reasoning
A. Reaction time affects the recorded interval. Repetition can reduce random variation, but it does not automatically remove a systematic effect.
Continue with examiner-style kinematics practice, where you must state limitations alongside plotted motion evidence.
Continue with the next resource in this course.
Course and syllabus information
- Course
- SEC G3 Physics
- Edition
- SEC G3 Physics 2027