IGCSE›Cambridge IGCSE Physics›Mind mapsThe EarthCambridge IGCSE Physics: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsDay and nightEarth rotates on its axis every 24 hoursSide facing the Sun has daylightSun's motion east to west is only apparentEarth rotates west to eastSeasonsEarth orbits the Sun every 365 daysAxis tilted at about 23.5°Tilted towards Sun: summer, longer daysTilted away: winter, rays spread over larger areaMoon's phasesMoon reflects sunlightOrbits Earth in about 27–29 daysPhases repeat every 29.5 daysNew moon: Moon between Earth and SunFull moon: Earth between Moon and SunThe Earthrotation and orbits24 h365 dv=2πrTv = \frac{2\pi r}{T}v=T2πrOrbital speedv=2πrTv = \frac{2\pi r}{T}v=T2πr2πr2\pi r2πr is the orbit's circumferenceEarth around Sun: about 30 km/sMoon around Earth: about 1 km/sThree timescalesRotation, about 24 hours: day and nightMoon's orbit, about a month: phasesEarth's orbit, about a year: seasonsExam tipsSeasons are not caused by distance from the SunConvert time to seconds, radius to metresWaxing is growing, waning is shrinking