Flight Sydney Airport departs from Sydney Sydney Airport at 14:30 and arrives at Melbourne Melbourne Airport at 16:05.
The flighttime is about 1h 35m. The distance travelled ("as the bird flies"): 787 Km. So the average speed is roughly 497 Km.
The best day to arrive at Sydney is Tuesday and it would be best to avoid Sunday, as prices are on average 114% higher than on Tuesday. (Average prices, based on 36737008 datapoints.)
We have a lot more statistics for flights JQ 609 and between Sydney and Melbourne.