Source

Collection

Wiki SR simulations — SuperSTEM special-relativity engine build.

Concept

Relativistic momentum p = γmv diverges as v → c, whereas Newton's p = mv grows only in direct proportion to speed. The two predictions coincide at low speed and split apart dramatically near the speed of light.

Serves

Shows that mass is not what "increases" — the momentum a given speed carries diverges because γ = 1/√(1−β²) blows up. The vertical gap between the two curves is the whole story; the speed of light is an unreachable wall.

Inquiry

At 90% of light speed, how much larger is the true momentum than Newton predicts? Where do the curves diverge, and why can v never reach c?

Misconception

That relativistic and Newtonian momentum stay essentially equal until you are right at the speed of light — in fact the gap is already more than double at 0.9c.

Pedagogy principles applied

ID	Principle	How it shows up here
H1	Misconception is structural, not a text card	The "they stay equal until c" and "only ~10% bigger" errors are wrong prediction choices; the rebuttal appears only if the student picks one.
D6/D7	Guided inquiry reveals in stages	Sidebar step-cards run predict → observe the split → verify the ratio → probe why c is unreachable; the curves stay hidden behind a "commit first" screen until the prediction is made.
Physics honesty	A function plot is not a particle	β is a static slider (drag the marker along the curve); nothing auto-sweeps velocity over time, since SR frames are inertial.
A2	Fewest objects	Opens with just the two curves and one draggable marker; readouts and the ratio bar appear only once the prediction is committed.
C	Every number earns its place	β, γ, p/mc for each rule and the Einstein÷Newton ratio are each read or compared by a step.