BowerR64 wrote:I really dont understand how it can shoot a tennis ball 100 yards in the air yet it can push a paper cup out without ripping it apart.
What does damage during acceleration (or equally, deceleration) is when forces have to be passed through the object.
Compare being in free-fall to being in a high end sports car.
Very few sports cars can out-accelerate gravity (1 G of acceleration is equivalent to 0-60 mph in 2.7 seconds), but even of those that only get halfway there, the acceleration can be a somewhat brutal experience.
Forces have to be transferred from the seat through your skeleton, ligaments, tendons and muscles in order for your body to be doing the same speed as the car.
In comparison, because gravity is pretty much constant (with very negligible differences between different parts of your body, unless you're in the vicinity of a black hole) and is directly proportional to mass, every single piece and part of your body accelerates completely evenly in free-fall.
(Take the ISS - anything that's in orbit of Earth is under Earth's gravity by definition. They're nowhere near far enough away to be out of the gravity well, so the reason you see all of those astronauts floating around in "microgravity" is just they're in constant free-fall, albeit a free-fall where they keep moving sideways in order to miss the planet.)
A similar principle applies to the paper cup. It's got almost all of its mass directly exposed to the pressure that's pushing it, so there's actually very little force being passed through it.
