I know in no time, patricks gonna smell something in the air and throw a couple more zeroes on this engage distance, but here it is for now...8000 engage.
That's like simple ballistics. When you throw something up with negligible drag, it comes down at the same speed as when you released it at the same elevation.
Radioactive torso's description should be, "You have cancer like wow."
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Yes, dafe, it is not surprising that it achieves an approximately equal velocity on the downward journey.
The notable points is that it surpasses the previous maximum speed the frame before it impacts.