<p>hehehehe</p>
<p>I am running over our trebuchet when it is done, and daughter is taking pictures of the other projects, so if the kids that got As used downloaded plans we can beat them up!! jk kidding</p>
<p>One kid told my D that at about 9pm last night his group gave up and played video games while mom struggled in the yard with the stoopid weapon.</p>
<p>I think we should put teachers car as the target!!! yes!!!</p>
<p>I’ve liked trebuchets ever since I saw that episode of Nova that started out with one flinging a piano about 200 yards. I thought now THERE is an interesting machine.</p>
<p>I don’t have much trebuchet advice beyond what has already been given, other than to emphasize that the angle of the sling hook is the key to release at the proper time and hence to achieving maximum distance.</p>
<p>I have a lot of sympathy for you in spending a weekend on last minute physics projects. A week ago I spent a lost weekend similarly trying to help D2 design and construct a “Slowler Coaster” - a ramp or tube that would keep a marble in continuous downward motion from a height of 7 feet for 60 seconds, all built on a base of no more than 3 feet in diameter. 60 seconds turns out to be a VERY long time to keep a marble rolling. The viscous liquid approach (remember those old Prell commercials?) was not allowed. Three trips to Home Depot for parts and my best efforts to help topped out at 43 seconds.</p>
<p>Hey, here’s something with the sling - if two strings attach the sling to the arm, one of them should actually come loose as it launches. Attach it to a nail that can rotate, then you can change when it comes loose. This was my high school’s design for a nationally placing Trebuchet in Science Olympiad. You can probably find more advice on the Science Olympiad message boards at <a href=“http://www.scioly.org%5B/url%5D”>www.scioly.org</a></p>
<p>Re Wheels: tell them you got a skateboard at a garage sale today for 50 cents!!</p>
<p>Some friends of mine built a trebuchet that could launch a pumpkin 380 yards. It consumed ALL of their energy for months on end.</p>
<p>I’m curious–why would putting the trebuchet on wheels increase the length of the fling? (Obviously not a physics geek)</p>
<p>I dunno, I would think it’d reduce it because more of the energy would be absorbed from the moving of the device instead of it creating more energy.</p>
<p>But mine had wheels, but only for decoration, they didn’t actually work.</p>
<p>As for not downloading plans, screw that. How are you supposed to make a trebuchet without plans? You’d have to at least look up how one even worked.</p>
<p>When we got the project some people didn’t even know what a trebuchet was, much less how one worked.</p>
<p>The NOVA video tape has a table top demonstration of the effect of wheels on a treb. It was quite interesting. Physics of forces hasn’t changed much in the last 1000 years.</p>
<p>Would someone mind posting some video and sharing the link of the finished item in action? </p>
<p>FWIW, there are plans of a cheap PVC pipe based trebuchet at:</p>
<p><a href=“http://www.trebuchet.com/plans/pvc/[/url]”>http://www.trebuchet.com/plans/pvc/</a></p>
<p>thats what we built, with some adjustments, but still don’t won’t very far!!!</p>
<p>My H is so mad…all our weekend plans cancelled!!! blech to teacher, who himself was in Napa all weekend…</p>
<p>bandit - </p>
<p>“Physics of forces hasn’t changed much in the last 1000 years.”</p>
<p>Thanks heavens there is some consistancy in life.</p>
<p>A few questions here: which is more important? Meeting the goal of throwing an object a certain distance or learning something about the physics of the thing? Why are the parents so involved in making the thing work? Is it possible the teacher has two goals in mind: learning a little physics and learning to work through frustration?</p>
<p>
</p>
<p>Nonsense. The velocity of time is clearly accelerating. And there seem to be some dubious expansions of mass, often accompanied by a corresponding thinning of hair.</p>
<p>but with the thinning of hair comes the thickening of the belly, so mass remains constant</p>
<p>or, as hair thins on the head, it “appears” in the ears and nose, so again, no loss of mass</p>
<p>;)</p>
<p>THEY GOT A B!!! AND THEY HIT THE TEACHER WITH THE TENNIS BALL!!! YEAHH!!!</p>
<p>A BEEEEEEEEEEE :)</p>
<p>Phew</p>
<p>Thank you all!!! Man, they could have gotten a D, but it worked!!! The girls wanted to cry with joy!!!</p>
<p>LOL! “hit the teacher with the tennis ball…” Glad it worked out.</p>
<p>Or hurl the teachers car. Google Hillman and trebuchet.</p>
<p><a href=“http://www.manatarmsbooks.com/trebuchet.html[/url]”>http://www.manatarmsbooks.com/trebuchet.html</a></p>
<p>A 1975 2 dr Hillman, to be precise <grin></grin></p>
<p>Next, they should see how far they can hurl the teacher.</p>
<p>YEAH!! I will suggest that…I am sooooo glad that project is over. And the kids would love to hurl the teacher!! Right into the big old dumpster holding all the trebuchets…yep everyone of them was torn apart tossed and the parts recycled…my D wanted to run hers over, but I was afraid the over abundance of duct tape would trash my car wheels</p>
<p>Making icecream for chemistry was so much more fun.</p>
<p>Or the egg drop</p>
<p>Or the sled</p>
<p>Or the luge run</p>
<p>Or the science fair</p>
<p>I don’t have any advice for you, Citygirlsmom but just some hugs and understanding. Sucky weekend. I opened this thread and did not even know what a trebuchet was…I thought this was some project on some French political person or some such! Silly me. My D took AP Physics and this was not a project, thank God. I have an entire basement full of school projects from two kids over the years…countless hours these things take. Today is the last day of school for my youngest child and while some of the projects were fun to work on, I am not sure I am gonna miss some of it either. </p>
<p>I’m glad your D got a Beeeeeeeeee. I kinda don’t like the grading based on the distance alone and not the effort or the project itself. I can see how there would be some points for a better working trebuchet but dunno if I like that as the sole grading criteria. It kinda reminds me of back in high school in gym class. I will never forget that our grade was based on the difficulty of the gymnastics routine…if you did a roundoff dismount (no way could I do these things) in the routine, etc., it was an A, and so on down the line. Yikes. </p>
<p>I also do not like projects of that magnitude to be assigned and only have the one weekend to do it. That does not allow for time management but rather, forces one to do it in a relatively short period of time when other things are going on in their lives. Missing a family trip or graduation event should not have to happen. If the kids were given a week, they could have planned around other responsibilities, etc. I realize the course is condensed but the time to do such a project is substantial and to require it all take place on a weekend, is not right in my book. I hear your angst and I feel for ya. It is over now, thankfully, and one more story you can tell about her schooling and projects, etc. </p>
<p>Susan</p>