Physics A-Level
Period–semi-major-axis relationship
What Period–semi-major-axis relationship means in Physics A-Level, as defined for OCR.
Definition of Period–semi-major-axis relationship
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Reference: OCR
The square of the orbital period T is proportional to the cube of the semi-major axis a, so T²/a³ is constant for all planets orbiting the same central body.
Topics that use Period–semi-major-axis relationship
- Planetary motion (OCR A-Level)
Related terms
- Circular orbital motion
- Equal areas in equal times
- Geostationary orbit
- Geosynchronous orbit
- Gravitational force as the centripetal force
- Uses of geostationary satellites
- Derivation of Kepler's third law
- Elliptical planetary orbits
Using Period–semi-major-axis relationship in the exam
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