Flight Sydney Airport departs from Sydney Sydney Airport at 12:00 and arrives at Melbourne Melbourne Airport at 13:35.
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 Wednesday and it would be best to avoid Saturday, as prices are on average 64.01% higher than on Wednesday. (Average prices, based on 36443320 datapoints.)
We have a lot more statistics for flights GA 838 and between Sydney and Melbourne.