IGCSE Physics: Scale, Gravity and Orbits | Edexcel Modular | Unit 9 | L1

IGCSE Physics: Scale, Gravity and Orbits | Edexcel Modular | Unit 9 | L1

This lesson covers spec points 9.2–9.5 of the Edexcel Modular IGCSE Physics specification — the scale and
structure of the universe from the solar system to galaxies, and gravitational force as the cause of orbital
motion for moons, planets, comets and artificial satellites, including the differences between their orbits.

PowerPoint includes:
• Retrieval starter reviewing forces and gravity from earlier units
• Direct Instruction (I Do) — our place in the universe established (solar system → galaxy → universe);
examples of galaxies; the structure of our solar system; gravity introduced as the force that keeps
objects in orbit; how orbital radius relates to orbital period
• Guided Practice (We Do) — guided tasks comparing the orbits of moons, planets, comets and satellites
and the role of gravity, with answers revealed after each attempt
• Check for Understanding — 3 MCQs on scale, orbital motion and gravity; answers on following slides
• Independent Practice (You Do) — activity sheet with exam-style questions
• Review and Reflect — exit ticket on orbital motion

Activity Sheet includes:
• Exam-style questions progressing from describing the scale of the universe to explaining how gravity
governs orbital motion and comparing different types of orbit
• A stretch question requiring higher-demand application
• Full mark scheme for teacher use