The two benches. Dynamics track is a cart on a track — tilt it, add friction, clip on a hanging mass, spring launcher, or photogates, and let the cart fly off the table edge. Ball launcher fires a ball through the air; drag photogates anywhere in its path. Switch benches with the tabs at the top-left.
Setting up. Every setting in the Setup panel has a slider and a type-in box — type an exact value and press Enter. Settings marked ? unknown are hidden because finding them is the point of the lab.
Running. Press ▶ Run to start, again to pause, ↺ Reset to rewind. The chips on the stage show live readings (time, speed, measured acceleration, gate readings, range, max height). Use the Speed menu to slow the sim down and watch closely, and the 2D/3D switch to orbit around the scene (drag to rotate, scroll to zoom — photogates are dragged in the 2D view).
Photogates. Drag them along the track or through the flight path. A gate reads the speed of whatever passes through it — exactly like the real thing.
Live graphs. Tick the quantities you want (position, velocity, acceleration…) and they stream in real time while the sim runs — just like watching the Cart Reader. These reset every run.
Recording trials & the fit. After a run finishes, press ＋ Record trial to save one row of results. Change one setting, run again, record again. Then choose what to plot — the graph draws your trials as points and fits a line of best fit through them. The readout shows its slope, intercept, and R² (how close the points are to a perfect line — aim for 0.99+). Most labs are designed so the unknown IS the slope (or comes from it with one multiplication) — that's how scientists extract values from noisy data.
Labs. Pick a lab from the dropdown. Each has a goal, steps you can reveal one at a time, optional hints, and an answer box that checks your measured value. Press New unknown to re-randomise and practice again.