How long at high altitude.
Today I watched a Tornado pass over at high altitude.
It took 'longer' to move out of my field of view than if it had been 'just skimming the rooftops' (which is the usual transit where I live on a low-flying corridor).
My question is simple - ignoring the time taken to get to altitude (and descend), is there a difference in time taken between A and B at 50,000 ft and 500 ft?
What is the limit of cruising speed at 500 ft and 50,000 ft - does the speed of sound limit how fast aircraft can travel at altitude?