- #1
sheepcountme
- 80
- 1
Homework Statement
A planet has an eccentricity of 0.006800 and a semimajor axis of 0.7233 AU, find the ratio of ortibal speed at perihelion to that at aphelion.
Homework Equations
d=e x a
L=mvrsin[tex]\theta[/tex]
The Attempt at a Solution
I plugged in and solved for the distance between the foci (0.004918)
and then set the angular momentum constants equal to each other:
m v(p) rmin sin[tex]\theta[/tex]=m v(a) rmax sin[tex]\theta[/tex]
the masses and sin[tex]\theta[/tex] cancel out, so
v(p) x r min = v(a) x r max
and so the ratio is:
v(p) / v(a) = r max / r min
r max is the semimajor axis, and r min is the semimajor axis minus the d as found above:
So, it should be .7233/.718382 which gives me 1.00685, but this was incorrect according to my online homework, could you tell me what I did wrong?