The orbit of Pluto is elongated with an eccentricity of 0.25. What is the approximate ratio of Pluto's orbital speed at perihelion to its orbital speed at aphelion?

1 Answer
May 24, 2016

#sqrt (5/3)#

Explanation:

Use #v=sqrtmu((2/r)-(1/a))#, perihelion = #a(1-e)# and aphelion #= a(1+e)#.

Here e = 0.25, approximately.

Now, for any planet, the ratio of the speeds at perihelion and aphelion becomes

#sqrt((1+e)/(1-e))# and here it is #sqrt( 1.25/0.75)=sqrt(5/3)#.