Kids science projects

[DonW]

Last time was just a simple gram balance scale. This was a easy A since 1ml rodi water weighs exactly 1 gram.

Here's the new tough one. Its a catapault to chuck a golf ball. Who ever sends the ball further wins.
My question to the kids science teacher was "is there a maximum ball velocity". I got a real desire to grunt when I found out there was "no limit".

I have these two spring loaded tensioners. Each requires 200ft lbs at 24" from center to pull all the way back. I figured the arms would be 2.5 ft long and stop at 92 degrees travel. So the question is how do I determine the velocity of travel. The goal is about 800 yards but not over 1000. :lol:

Don

 

[bswim]

Could always make a cannon and shoot them out, if the teacher complains just tell him to quit living in the dark ages and that there's this thing called technology advancement, LOL.

Seriously, I'd be careful how you contain those springs, those things could do some serious damage if they came loose and shot out sideways. Look around for that guy that was launching all kinds of huge things with that catapault that was about 20 feet tall. Might get some ideas and scale it down.

 

[DonW]

Could always make a cannon and shoot them out, if the teacher complains just tell him to quit living in the dark ages and that there's this thing called technology advancement, LOL.

Seriously, I'd be careful how you contain those springs, those things could do some serious damage if they came loose and shot out sideways. Look around for that guy that was launching all kinds of huge things with that catapault that was about 20 feet tall. Might get some ideas and scale it down.

I love overkill when it comes to the girls projects. It always seem the boys are do much cooler stuff and get all the extra credit points. I personally think this is do to fathers not giving girls the same type of help they would give boys.

Don

 

[big t]

Sounds like fun

 

[bswim]

I fully understand being the parent of a 7 year old daughter thats an only child

 

[NaH2O]

Ah - my daughter is in real trouble when it comes time for science projects.....with a Mom that has a strong science background and an engineer dad from an engineering family - she's going to be overkilled on projects . Don, I'm not sure you have enough information to determine the velocity at this point?

Here's an interesting PDF file for a team that won best engineered catapult among other prizes: http://www.pultruders.com/activities/pdf/presentation_fin.pdf

Here's a website that has catapult designs - don't know if it will help or not, but maybe the photos will inspire you: http://www.redstoneprojects.com/trebuchetstore/build_a_catapult.html

 

[NaH2O]

Oh, here's a website with information on determining velocity: http://physics.webplasma.com/physics04.html Physics is Phun! yes...I'm a geek!

Let us know how the project goes!

 

[Shoreliner11]

It would still be pretty tough to calculate the velocity. Using the second formula would be the first step in finding the acceleration but keep in mind that you would have to find the time between when the catapult is released to when the object leaves the catapult because after that there is only gravity and air resistance acting on the object. Even though the acceleration is most likely not constant it should still give you an idea. If you could find that then plug the time, acceleration and initial velocity (which is 0) into the equation you could get your velocity. Because of the speed of the catapult I doubt you could get a really accurate reading but a rough estimate is still good. Have fun.

 

[Alice]

Sheesh, Don; and here I thought I done good helping my daughter construct a battery-life test with little motors, spinning colored discs and a timer, LOL.

Nikki, my husband is a geek, too. He reads quantum physics "for fun." I just smile and nod alot when he talks to me about it.