Rough thumb calcs: Mach 6 is apx 3K MPH (4K True Airspeed but I’ll use the lower).
Cross the USA: 1 hour 15 minutes
Circumnavigate the globe at the equator: 8 hours
YMMV.
That is movin’ folks.
WTF is the difference between air speed and true air speed? Mach 6 is about 4,000 – 4,500 mph depending on the altitude. The speed of sound at sea level is about 760 mph, but it decreases with temperature. At 60,000 ft (where this thing will probably fly) the speed of sound in about 660 mph. That would put Mach 6 at 3,960 mph.
imho . . .
from what my relative assured me . . .
we have craft that routinely go much, much faster than that
and have since AT LEAST 1970.