maximum strength in a catapult

[rigadin]

Hi guys,

at school there is a competition between all classes, we have to build a catapult with 300 ice cream sticks (popsicles), 5 elastic bands and 1 thin metal stick. we have to make a ping pong ball fly as far as possible. We already have a design but can you please help me with important details and things that make the ball fly far!

Thanks for your help

rigadin

Edited April 15, 2010 by rigadin

[Newbies_Kid]

Launching angle should be set at 45 degree for maximum range.

 

[Mr Skeptic]

Two things:

1) optimize the launch angle (45 degrees assuming no air friction).

2) maximize the launch velocity. This means that you either make the arm longer, or the torque stronger, or both.

 

Depending on how your elastic bands work, you might not want to make your catapult like a real one that relies on twisting ropes, and instead make it more like a slingshot (if allowed). In any case, you want to use your catapult arm as a class 3 lever.

[Newbies_Kid]

May be you should design the catapult's cup and arm properly, i don't know whether its correct or not but i think that you should minimize the vibration (after you launch an object) of the arm as much as you can for maximum kinetics force.

[rigadin]

Two things:

1) optimize the launch angle (45 degrees assuming no air friction).

2) maximize the launch velocity. This means that you either make the arm longer, or the torque stronger, or both.

 

Depending on how your elastic bands work, you might not want to make your catapult like a real one that relies on twisting ropes, and instead make it more like a slingshot (if allowed). In any case, you want to use your catapult arm as a class 3 lever.

 

Hi, thanks for the help but I don't understand everything. Which part is the torque? what is a class 3 lever? thanks for your help

[wanabe]

rigadin,

I think since you are launching a ping pong ball you want the catapult to have a long smooth throw rather than a short fast one.

 

From my experience when you hit a ping pong ball hard it tends to swerve quickly so it won't go as far, but it will go quick. If your goal is distance...

 

What are you allowed to use to hold the sticks together?

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well judging by the date its probably over and done with, how did it go?