Terminal velocity as pertains to a falling object in a vacuum?

Question

I've been thinking again... When an object is dropped, it accelerates until the pull of gravity and the wind resistance equal out (terminal velocity) resulting in a constant speed of free fall. I know this might be an impossible scenario, but what would happen if a bowling ball was dropped from 100,000 feet on a planet that had no atmosphere (a vacuum)? I mean, if there's no air to create resistance, would the ball just keep accelerating indefinitely until it hit the ground or would it eventually stop accelerating? Is gravity an "endless attraction" or does it only pull objects at a certain speed? I know the closer to a planet you get the greater the pull of gravity becomes--maybe this fact plays into my question... Any physics geniuses please get this riddle out of my head! Thanx!

Answer 1

The object, in theory, would continue to accelerate towards the planet. Another point to ponder is the effect that the planet's orbit would have on it's trajectory. And as you mentioned, the closer the two objects got, the greater the gravitational effect - so this becomes a non-linear acceleration as well.

OK. Time for me to get some sleep. If I get some 'eureka!' revelation at 3am, I'll be back with an edit. If not...well...good luck proving this with an experiment...   :-)

Answer 2

Let us assume that we have to consider the gravitational force from that planet as the o nly force.Let us also assume that the speed remains very small compared to speed of light - so we do not need to invoke theory of relativity.

If the above assumptions are valid, then the ball will go on accelerating till it hits the planet. The acceleration is not constant. Rather it increases because gravity is stronger at a point closer to the planet. Therefore the speed of the ball will increase at a faster rate.

Gravity has nothing to do with speed.

Answer 3

When you solve for the gravitational acceleration of any given mass the solution is given in meters per second per second. For example, on Earth it's 9.8 m/sec/sec. If your bowling ball was dropped from 100,000 feet and Earth had no atmosphere, the ball would gain 9.8 meters per second of velocity every 9.8 seconds it fell.

Answer 4

it would continue accelerating, black holes are perfect examples of this, ultimately though the top most "speed limit" is the speed of light. so i suppose you can consider that the default terminal velocity of any object.