# Thread: Help my ignorance on trajectory

1. Objects achieve maximum distance with their arc when it's projected at 45 degree angle. How come in football when someone kicks a really long field goal they kick it at a lower angle?
I read that the backspin on the ball gives it more lift, (ie: 30 degree kick becomes 37-40 degree) and wind becomes a factor. But just hypothetically, let's say there is no wind whatsoever, what then? If you kick it with less backspin for lift/slowing the ball and at a 45 degree angle, would that not mean that it would go further?

I'm trying to understand why it is this way, it just seems to conflict with physics.. If wind wasn't a factor and you didn't have crazy backspin, 45 degree should have the longest arc shouldn't it?

Reason I'm asking is cause on Maddon 2010 kicking at a much lower angle (all the way down) allows you an extra 5-7 yards on your kick, and I've heard it's the same way in real life.

Sorry for such an unscientific post for my first one hah. I've looked around the internet and I can't find a football site with the response I'm looking for. They're just all beating around the bush and pretty much accepting it as an axiom.

2.

3. Originally Posted by takenaptly
Objects achieve maximum distance with their arc when it's projected at 45 degree angle. How come in football when someone kicks a really long field goal they kick it at a lower angle?
I read that the backspin on the ball gives it more lift, (ie: 30 degree kick becomes 37-40 degree) and wind becomes a factor. But just hypothetically, let's say there is no wind whatsoever, what then? If you kick it with less backspin for lift/slowing the ball and at a 45 degree angle, would that not mean that it would go further?

I'm trying to understand why it is this way, it just seems to conflict with physics.. If wind wasn't a factor and you didn't have crazy backspin, 45 degree should have the longest arc shouldn't it?

Reason I'm asking is cause on Maddon 2010 kicking at a much lower angle (all the way down) allows you an extra 5-7 yards on your kick, and I've heard it's the same way in real life.

Sorry for such an unscientific post for my first one hah. I've looked around the internet and I can't find a football site with the response I'm looking for. They're just all beating around the bush and pretty much accepting it as an axiom.
You get the longest distance at a 45 degree angle IF there is no wind resistance (i.e in a vacuum) and if the altitude of the launch point and the landing point are the same (i.e. the trajectory starts and stops on a plane). If either of these conditions are violated the solution is quite a bit more complicated.

If there is wind resistance or lift involved then the optimum angle will be other than 45 degrees. Back spin and wind will create a fairly complicated scenario, since a football is not spherical., but the net result should be a little lift.

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