How far can you throw a basketball off a dam?
Well, the answer depends on if you know the magnus effect or not.
If don't know it you would probabily throw as you always throw a ball. And then you would realize that you have thrown the ball just some meters more than usual.
If you know the magnus effect you wouldn't throw it at all; you just would drop it with a backspin. But the result is amazing: far more than hundred meters (result in the video: 140m);
Watch the video:
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In this video the magnus effect is explained one more time: