Question

what is the expression of velocity of earth at perihelion. Is it (GM/a-ae)61/2 ?

Answer 1

I would use,
\[v=\sqrt{\frac{(1-e)\mu}{(1+e)a}}=\sqrt{\frac{(1-0.00355) 1.32\cdot10^{20}}{ \left((1+0.00355) 149.6\cdot 10^9\right)}}=29.6\ Km/s\]

Answer 2

First, that looks like aphelion not perihelion

for perihelion, use (1+e)/(1-e)

also, e is about 0.0167
http://en.wikipedia.org/wiki/Orbital_eccentricity#Examples

Answer 3

Yes I took and old value and the aphelion velocity, sorry. ;)