**1. Asking because the answer I got seems too simple...a planet of mass m moves in an elliptical orbit about the sun. The minimum and maximum distances of the planet from the sun are called the perihelion and aphelion respectively. If the speed of the planet at p is v**

_{p}, what is its speed at a? Assume the distances r_{p}and r_{a}are known.**2. Relevant equations**

dA/dt = 1/2r

dA/dt = 1/2r

^{2}ω, ω=v/r**3. The attempt at a solution**

dA/dt is constant, so 1/2r

dA/dt is constant, so 1/2r

_{p}^{2}ω_{p}=**1/2r**_{a}^{2}ω_{a}. Substitute v = ωr, that gives 1/2**r**_{p}v_{p}= 1**/2****r**_{a}v_{a},**v**_{a}= r_{p}v_{p}/r_{a}. Is this correct?