Luke Allen
Reputation
Top tag
Next privilege 50 Rep.
Comment everywhere
 Apr 13 comment Projectile motion, solving for x and y when reflected by a given point at a given angle I meant that I'm inputting radians, not degrees, and it's not working. I just realized your equations were counting on radians the entire time anyway. I have no clue why all methods aren't working. Perhaps it's because on a computer, Y values get bigger as you get lower on the screen, and less as you get higher, which is the opposite of a typical plot graph. I tried reversing some + and - signs in the equations to account for this, it worked for the normal trajectory, but with the line-reflection part, nothing even came close to an accurate result Apr 13 comment Projectile motion, solving for x and y when reflected by a given point at a given angle David, thanks so much, I hate to ask for more, but I've tried implementing the first way and alternative way (equations 3 and 4) into coding but nothing is working. I'm sure, after much trial and error, I've got the equations in exactly as you have them, with one exception: I have to put the angle in as radians, since my prog lang doesn't support cos(Degrees) or sin(Degrees), the number must be radians there. Could that be causing the problem? The trajectory plots correctly up until I try to account for a line obstructing it. Apr 12 comment Projectile motion, solving for x and y when reflected by a given point at a given angle David, the more I think about it, shouldn't it be possible to plot the x and y without calculating the impact angle and velocity with the line? The horizontal velocity doesn't change since there is only downward gravity, and in the case of colliding with a perfectly vertical line, the trajectory is mirrored by the vertical, no matter what impact angle there is. I ask out of curiosity only Apr 11 comment Projectile motion, solving for x and y when reflected by a given point at a given angle Yes, I understand perfectly now, this question has been on my mind for two weeks. I always thought it was possible to calculate the resultant angle after collision based on the initial angle, initial velocity, and initial position alone - without calculating the $/theta \, 1$ and $v 1$ as you call them, but now I see. Thank you, I'm sure this will help others too, very clear manner of answering! Apr 11 comment Projectile motion, solving for x and y when reflected by a given point at a given angle This seems exactly right, thank you!! Apr 11 accepted Projectile motion, solving for x and y when reflected by a given point at a given angle Apr 11 comment Projectile motion, solving for x and y when reflected by a given point at a given angle David K, I've made an edit to the original question and added an image for explanation Apr 11 revised Projectile motion, solving for x and y when reflected by a given point at a given angle added 857 characters in body Apr 11 asked Projectile motion, solving for x and y when reflected by a given point at a given angle Jan 2 accepted Can two regular tetrahedrons make an octahedron? Jan 2 asked Can two regular tetrahedrons make an octahedron? Nov 15 awarded Curious Sep 21 awarded Popular Question Aug 31 awarded Popular Question Aug 21 comment The puzzle of billiard geometry Your personal beliefs, labels, and viewpoints of the world in general are of no relevance or importance to me, why can you not see that? I've been here a long time, I know that it's common to only provide hints, that doesn't make it good Aug 21 accepted The puzzle of billiard geometry Aug 21 comment The puzzle of billiard geometry taken from the about page of stackxchange math: "Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's built and run by you as part of the Stack Exchange network of Q&A sites. With your help, we're working together to build a library of detailed answers to every question about math." That's right, detailed "answers", not one-liner hints and references to wiki pages. Aug 21 comment The puzzle of billiard geometry this is a question and answer site, not a question and hint and learning site, no matter what your personal agenda is, that is what the site is about. I don't care for your personal agenda. GTFO. Aug 20 comment Separating 18 people into 5 teams 10 times easier for anyone else to copy and paste into wolfram alpha and learn from, and 10 times more irrelevant if it takes 10 extra seconds to read the single sentence. Aug 20 comment Separating 18 people into 5 teams much easier to copy plain text to wolfram alpha than formatted mathjax