563 miles per hour is 489.234 knots.
17 knots=19.56 mph
i knot in mph is 0.868976242 knots so 503 mph is 437,095049726 knots
11 knots = 12.65 mph
16.6 knots is about 19.1 mph
1,040 mph = 903.73 knots
356 mph = 309.35 knots.
317 mph = 275.5 knots
1.5 knots = 1.7 mph
3.47590496 knots = 4 mph
74 knots is 85.1577 MPH
437 knots = 502.9 mph
About 46 mph