IGCSE Physics: Orbital Speed Calculations | Edexcel Modular | Unit 9 | L2

This lesson covers spec point 9.6 of the Edexcel Modular IGCSE Physics specification — using the orbital
speed relationship v = (2 × π × r) / T to calculate orbital speed, orbital radius or time period for planets
and satellites.

PowerPoint includes:
• Retrieval starter linking speed = distance / time to circular orbits
• Direct Instruction (I Do) — the orbital speed equation built from s = d/t; formula triangle for
rearranging; visualising the variables; unit conversions (km to m, hours/days to seconds); two fully
worked examples (finding orbital speed, then rearranging to find time period T)
• Guided Practice (We Do) — three guided calculation problems progressing in difficulty, with full
working revealed
• Check for Understanding — 3 MCQs on rearrangement, units and calculation; answers on following slides
• Independent Practice (You Do) — calculation activity sheet
• Review and Reflect — final task and exit ticket

Activity Sheet includes:
• Calculation-focused exam-style questions covering finding orbital speed, radius and time period, with
unit conversion required
• A multi-step stretch question
• Full mark scheme for teacher use, with symbol-form rearrangements shown

Key formula: v = (2 × π × r) / T