Hey all,

 

does anyone know where I can get decent information on the physics of catapults?

 

thanks.

if you want to build a catapult, might i suggest you try tribuchets instead? They are much easier to build and, i think, much more satisfying to use.

Trebuchets are hilarious.

 

Especially if you happen to have a pile of dead cows.

I have 5!

why are the two UK'ers with the freakiest avatars talking about dead cows and Trebuchets?

Trebuchetting dead cows is hilarious, that's why.

 

Especially if they are on fire, and you aim over the keep.

We had a trebuchet project in Gr. 12. We had to aim a penny and have it drop into a bucket. It's pretty amazing what Kinematics and Projectile motion can do.

 

SItes?

My friend borrowed my binder, and hasn't given it back yet...It had some good handouts...

 

Here's a site I bookmarked from last time though:

 

http://www.trebuchet.com/plans.html

 

MrL_JaKiri said in post #4 :

I have 5!

 

Cows or trebuchets?

haha, I saw these on the discovery channel when they were airing a pumpkin launching contest.

I've seen a grand piano launched from one.

 

It's surprising how well it flew, but the landing left a lot to be desired.

I built a trebuchet once. it was 12 feet tall and I launched bricks and chairs over my neighbors lawn into the alley behind our houses... LOADS of fun!!!!

 

there is an old guy in the UK somewhere with entirely too much money and free time who built a GIGANTIC trebuchet out of telephone poles. he launched a flaming piano and a car with it. he has plans to build an even larger one using steel-tube roller-coaster support colums so that he can launch a double-decker bus!!!!!! I have GOT to get me one of those!!!!!

dang! I think I've seen the piano launcher as well. thats pretty sweet though. I can't imagine a bus actually launching though.

Some guy shot his fiencé out of one of those... or a catapult, or a cannon. I can't remember. Either way, she broke some bones and, well, the marriage plans were altered somewat after that particular event.

I think I was 3 or 4 and I took the green roof plank from my Lincoln logs and centered it on the 2" connector log. I put a 2" connector on the end of the plank and stomped on the other end to launch it in orbit. I wound up with a golfball knot on my forehead.

I still think if you want to keep kids safe, raise them inside a barrel but if you want em to learn, let em play with their toys and get their knocks.

Just aman

It's still not a good idea to launch your fiencé into orbit.

Sayonara³ said in post #3 :

Trebuchets are hilarious.

 

Especially if you happen to have a pile of dead cows.

 

Ermm...haha...O..k....

 

Anyway, yeah..i got round to building a catapult which works great. After doing testing with different arm lengths and masses etc, i found it surprising that the shorter the arm length, the further the object thrown lands. Whý is that? I thought that the longer the arm further the object lands.

 

Well yeah..but I'm just guessing, but heavier objects land at shorter distances due to Newton's second law of F=m.a

 

THanks.

For anyone who is confused about the trubuchet and dead cow comments:

 

The trebuchet, catapult and ballister are part of the medieval siege engine.

 

The function of a trebuchet was to launch very heavy loads at the enemy's fortifications with a great deal of force. When your opponents were all holed up in the keep of a castle, chucking dead and diseased animals in there was a very effective way of forcing them to flee or fight.

 

This was usually burning or rotting cows.

 

The trebuchet is also powerful enough to launch rocks at stone walls, and can cause serious damage to them in a very short time.

Did any of You hear about the guy who built a trebuchet and used it to fling himself and his friends ito large bodies of water? If I find where I read that, I'll post it.

 

(for those of you that read Scott Adams, ffffttt-ffffttt! and weasles away)