Red hulk jumps from the earth to space the timeframe is unknown, but I'll assume 20 seconds cause Red hulk had enough time for a mini conversation with Thor before they stopped jumping up and started fighting. (they didn't really move a lot while fighting they just engaged in H2H) Then Thor gets knocked out and then we see the earth
average words per second is 150 red Hulk said a totaly of about 92 words which would be 37 seconds
14.7cm/768 = 5.4cm/X
14.7X = 4147.2
X = 282.12
Using AngelSizing Formula
2atan(tan(70/2)*(282.12/768))
I get 0.344653077722 Radians converting it to degrees I get 19.74716675 Degrees
The diamter of earth is 12742000 Meters
Now we use this Angular Size Calculator to find the distance
http://www.1728.org/angsize.htm
36604000 Meters
36604000/37
989297.297297 Meters a second or Mach 2907.22