Ignoring drag, terminal velocity and friction, input 1143 seconds here: http://keisan.casio.com/exec/system/1224835316 It yields a velocity of 11.2 km/s (Earth's Escape Velocity) at freefall from a height of 6.4 km (a fraction of the height/depth of Everest, Antarctic ice cap and deepest oceanic depth). Consider a 6.5 km Vaccum filled vertical tube with a half circle at the bottom which a ball could roll at the bottom and redirect upwards after freefall through it. Such a ball will have a velocity greater than the escape velocity at the bottom of the tube. This can't be right since considering the tube be a complete U shape then at top/end of the path the speed would be the same as the start of the path namely 0 and no escape would be achieved. Where did I go wrong? Thanks in advance.