Key Equations

Key Equations

Kepler’s third law T12T22=r13r23T12T22=r13r23
eccentricity e=fae=fa
area of an ellipse A=πabA=πab
semi-major axis of an ellipse a=(ra+rp)/2a=(ra+rp)/2
semi-minor axis of an ellipse b=rarpb=rarp
Newton’s second law of motion F=ma=mgF=ma=mg
Newton’s universal law of gravitation F=GmMr2F=GmMr2
acceleration due to gravity g=GMr2g=GMr2
constant for satellites orbiting the same massive object r3T2=GM4π2r3T2=GM4π2