So technically the man begins to move perfectly horizontal from where he became weightless on the earths surface. If you where to stand beside him though as it happened it would look as if he his simply going straight up. In a way the man is traveling both sideways and upwards due to the earths curvature. The earth's rotation is fast enough to counteract his sideways motion fairly well so it he's still on the same space of the earth( Also the reason why you land on the same spot when you jump
). His upwards motion is due to the earth curving away from him rather than his linear velocity which is why he wouldn't shoot off from the earth at 465.4211339 metres per second. It would take about 3437.746771 seconds for someone to leave the atmosphere from sudden immunity to gravity ( or 57.29577952 minutes). So relatively to a person seeing him going upwards, to them and himself he'd be traveling at 58.17764173 metres per second into the atmosphere. That's from start to finish if no unbalanced external forces act upon him. So the second gravity stops you blast off into the atmosphere at around 130 miles per hour. Technically you aren't actually moving but since everything around you including the air is at the speed it's the same effect. Theory of Relativity and all that.I'm not sure how good that is for the human body. Of course air resistance would come into it. It might actually emulate gravity for a bit because around 60 metres per second is a sky divers terminal velocity ( where air resistance and gravity cancel each other out and you retain the same velocity) but as you gained more downward velocity your relative deceleration would lessen which means while you do slow down the rate at which you do so lessens with along with your speed meaning you still might end up in space. So as long as you don't hit an airplane or are indoors it's a one way trip to space. Although if you were indoors or hit a plane you'd probably die from impact depending on the speed and even in a straight shot to space you'd probably die from suffocation or get messed up by the pressure before reaching the vacuum.
Your clothes and shoes might have enough mass to overcome air resistance and give proper downward velocity so you don't exactly 'blast off' but I'm not really sure. In theory they should I suppose given that they'll accelerate at 9.8 metres per second. I really don't know though.
I think I've done my math right but there's a lot of variables and unknown quantities. If you could actually nullify an objects gravity and study what happened it'd make for some great experiments. Still that 58.17764173 metres per second just seems weird, but it should be right.... I hope.
