# Understanding how a projectile that moves in a parabolic path

1. Sep 28, 2010

### tatiana

I need help understanding how a projectile that moves in a parabolic path can have a point where a-> is parallel to v-> or perpendictular to v->
Is this meaning that the lines tanget to the path are perpendicular or the actuall path?
And i would think that both parallel and perpendicluar are ppossible, yes?

2. Sep 28, 2010

Re: Pr0j3ctil3$Why the unusual thread title? Looks like a password :) 3. Sep 28, 2010 ### Redbelly98 Staff Emeritus Re: Pr0j3ctil3$

Well, a is always pointing downard. So what would it mean for v to be either parallel or perpendicular to that?