Science Buddies: "Ask an Expert"

elin105 wrote:Hi! This sounds like an interesting topic, that has potential to go far. What grade are you in at school?

What type of catapult are you planning on using? For example, if you use a slingshot catapult, it may be more difficult to control the constant variables, but it will be easier to construct.

Don't forget to take into consideration that the shape and density may affect results.

Good luck with your project!

peteryoung wrote:I suggest you do some background research on the web, using
"trebuchet" as the keyword. There are serious hobbyists who
do catapult launches for sport, but I doubt they'd be likely to
be patched into the Science Buddies network.

I don't know what size catapult you are contemplating but be
forewarned: these can contain a lot of pent-up power and
having a well-built and safely designed catapult is extremely
important. If you get to the test phase, this should be done
in a location where property damage or injury to bystanders
(or to yourself) cannot be allowed to happen.

If there's not enough time to build and test a catapult (Dec 20

Hi, I have to interview a person for my science project, is it possiable to interview you? I would really apprciate it. I built my catapult already and i just need some expert advice. It would be great if we could schedule it tommarrow around 6p.m Dec, 19 Iam pretty flexiable soo... lets cordinate.
THanks

Peter Young

induced_discharge wrote:Hi MCC,

I have had the experience of building a trebuchet, slingshot, and crossbow ballista before and let me tell you they are a lot of fun. From your post it is hard to tell what level you are doing this project on, however a good understanding of newton's first 2 laws and more specifically gravity will be key to comprehending the mathematical side of the project. (Perhaps a short introduction on air resistance to explain possible discrepancies wouldn't hurt as well) As for the "fun" side, building a model out of wood would (pardon the pun) probably make the most sense for its easy connections and general cheapness, abundance and versatility.

If you are advanced enough to be trying to calculate the energy you initially impart on the object, then I would suggest a trebuchet as there is no need to worry about elasticity. Otherwise you are just trying to make the projectile launch consistently in which case I would suggest a slingshot design which should have a nice consistent release.

Good luck on your project and keep on updating.