A modular diagnostic that maps the exact force and motion misconceptions your students carry — not just the wrong answers. Pick the module that fits your current topic. Heatmap report delivered within 48 hours.
Standard assessments often miss the deeper conceptual errors that persist through Newton's laws. These patterns appear across many IB, AP, A-Level, and GCSE classrooms.
Ask students to draw a free-body diagram of a ball thrown straight up, just after it leaves the hand. Many will include an upward "force of the throw" that isn't there. The impetus belief is one of the most persistent misconceptions in mechanics — and the same error reappears in circular motion as a phantom "centripetal force" added on top of the real inward force.
Ask for the normal force on an incline. Many will write N = mg. On an accelerating elevator floor, the same error appears. Students memorise the formula without understanding the condition it assumes.
Ask whether the weight and normal force on a book are a third-law pair. Many will say yes — and that they cancel. This conflation of equilibrium with Newton's third law runs deep.
Push a box across the floor at steady speed. Many students conclude the applied force equals the net force — and that force sustains velocity, not acceleration. The Aristotelian belief hides in plain sight.
Each module is 14 multiple-choice questions, takes about 15 minutes, and requires no student login. You don't need to use all six — pick the one that matches where your students are right now.
Impetus beliefs, inertia-as-force, force/energy/momentum conflation, inanimate contact forces, system boundary errors.
Force–velocity proportionality, acceleration–velocity conflation, "ma" as a force on FBDs, net force errors, inertial frame misconceptions.
Mass–weight confusion, weightlessness myths, N = mg persistence, Newton's third law pairing errors, apparent weight confusion.
Missing forces, ghost forces, wrong-object forces, internal/external confusion, friction and tension errors.
Friction formula errors, sin/cos decomposition swaps, N = mg on inclines, connected-object constraint errors, axis-choice mistakes.
Third-law pair identification errors, the cancellation trap, unequal effects misconceptions, third law in applied contexts.
Within 48 hours of your class completing the diagnostic, we send you a complete misconception analysis — actionable, teacher-readable, and ready to use in your next lesson.
Colour-coded class heatmap showing performance by question and by student performance band (A–D). See exactly where understanding breaks down across the class.
Teacher-readable summary: which misconception clusters hit hardest, what they mean, and how your class distributes across bands.
Mapped to the specific misconceptions your students triggered — not generic revision advice, but the exact conceptual errors to address first.
What each band (A–D) means for your students, with specific teacher action items — from "ready to extend" to "needs foundational rebuilding."
| Q# | Concept Tested | Overall | A (12–14) | B (9–11) | C (6–8) | D (0–5) | Cluster |
|---|---|---|---|---|---|---|---|
| Q01 | Mass vs weight (Earth to Moon) | 68% | 100% | 83% | 57% | 33% | M3-A |
| Q02 | N3 partner of book's weight | 50% | 100% | 67% | 43% | 17% | M3-D |
| Q03 | Astronaut in orbit: gravity? | 45% | 80% | 67% | 29% | 17% | M3-B |
| Q04 | N when pushing down on book | 41% | 80% | 50% | 29% | 17% | M3-C |
| Q05 | N when rope pulls up on book | 36% | 80% | 50% | 14% | 17% | M3-C |
| Q06 | When does N equal mg? | 55% | 100% | 67% | 43% | 17% | M3-C |
| Q07 | What does a scale measure? | 50% | 100% | 67% | 29% | 17% | M3-E |
| Q08 | Scale: elevator accel down | 59% | 100% | 83% | 43% | 17% | M3-E |
| Q09 | Free fall: weight and N? | 41% | 80% | 50% | 29% | 17% | M3-B |
| Q10 | N3 pair: book on table | 45% | 80% | 67% | 29% | 17% | M3-D |
| Q11 | Scale always reads mg? (T/F) | 55% | 80% | 83% | 43% | 17% | M3-E |
| Q12 | Gravity zero in orbit? (T/F) | 64% | 100% | 83% | 57% | 17% | M3-B |
| Q13 | Push down → N > mg? (T/F) | 36% | 80% | 50% | 14% | 17% | M3-C |
| Q14 | N3 partner of N? (T/F) | 41% | 80% | 50% | 29% | 17% | M3-D |
Q05, Q13 — Band C/D: 14–17% correct. The N = mg persistence is severe in lower bands. Students default to N = mg even when an additional force changes the situation.
Q03, Q09 — Band B: 50–67%. The weightlessness misconception is not confined to weaker students — it persists well into Band B.
Q02, Q10, Q14 — Overall 41–50%. Newton's third law pairing errors cut across all bands.
Red cells mark the highest-leverage targets. Your class heatmap is generated from your students' responses and delivered within 48 hours.
I carried out a pilot test of the Physics Misconceptions Diagnostics with my Grade 11 (lower 6th) International Baccalaureate classes, as part of their revision for end of year exams. The tests covered Motion Foundations, Forces and Free-Body Diagrams - topics that are fundamental to the IB course as well as A’ level courses.
The tests were all set up by FundaFirst - all I had to do was point the students to web links. The students found the questions easy to access and to carry out. The information that came back from FundaFirst was incredibly useful, identifying areas where the class and/or individuals were weaker. These areas would have been much harder to identify without the tests. FundaFirst then provided concrete examples of how to address the misconceptions, with work sheets targeting these areas.
I will not hesitate to use FundaFirst’s diagnostic testing with future cohorts!
Fill in the form below. Tell us which module matches your current topic.
→You receive a diagnostic link + setup instructions within 24 hours. No student logins needed.
→Share the link with your class. Each module takes about 15 minutes.
→Class heatmap + cohort summary + remediation notes delivered to your email within 48 hours.
Tell us which module fits your current unit and we'll set up the diagnostic link within 24 hours. No commitment — this is a free pilot designed for teacher use and classroom feedback.
The diagnostic is grounded in physics education research, including the work of Hestenes, Arons, and Knight. Our physics content has previously been licensed by Cengage.
The Laws of Motion diagnostic is one of three FundaFirst diagnostics. If your students are still in the motion unit, we also have a Motion Diagnostic covering position, velocity, acceleration, motion diagrams, and the x/v/a graph chain. And once forces are in place, our Energy Diagnostic covers work, energy, conservation, the work-energy theorem, spring PE, and heat vs temperature. Same format, same 48-hour turnaround.
View the Motion Diagnostic → View the Energy Diagnostic →Further reading: The Force Inside the Object — a teacher-facing essay on force-velocity confusion and why students treat force as something an object carries.