Simulation of Circular motion
Circular Motion Simulation — Description
The simulation shows a moving object tracing a circular path across four real-world contexts: a satellite in orbit, a car on a roundabout, a ball on a string, and a Ferris wheel gondola. In every scene, the object moves at a settable, constant speed — but the live panel shows vₓ and vᵧ oscillating continuously, and the direction θ sweeping through 360°, making the core distinction between scalar speed and vector velocity immediately visible without any text explanation.
Two arrows update in real time on the canvas: a solid green arrow for velocity (always tangent to the circle) and a dashed orange arrow for centripetal acceleration (always pointing inward toward the centre). Students can drag the speed slider to change the magnitude and watch centripetal acceleration scale with v², and they can pause at any moment to freeze the vectors at a chosen position.
Suggested Class Activity — “Freeze Frame Challenge”
Suitable for GCSE Physics, roughly 20–25 minutes.
Setup. Display the simulation on the board. Start with the Satellite scene at default speed.
Part 1 — Predict before you pause (5 min). Ask students: “If I pause the simulation when the satellite is exactly at the top of its orbit, which direction will the green arrow point? Which direction will the orange arrow point?” Students sketch their predictions on mini whiteboards or in books before you pause it.
Part 2 — Four positions, four sketches (10 min). Students work in pairs. Pause the simulation at four positions — top, right, bottom, left. For each, they sketch the circle and draw both vectors in the correct direction, labelling v and a. They then write one sentence explaining why the arrows are always perpendicular to each other.
Part 3 — Switch scenes, same question (5 min). Switch to Ball & String. Ask: “The speed hasn’t changed — has velocity changed? What provides the centripetal force in this example?” Take two or three verbal answers; use the live vₓ/vᵧ bars to show components shifting even though the bar for |v| stays fixed.
Exit question (3–5 min). “A car goes around a roundabout at a constant 30 km/h. Is it accelerating? Explain using the words speed, velocity, and direction.” Collect on slips or as a quick written response.
The simulation directly scaffolds the exit question — students have watched speed stay constant on the display while every other quantity changed, so the answer follows from observation rather than rote recall.