Help with my Science Fair Project?

Question

I'm using an idea from the book "Vaccum Bazookas, Electric Rainbow Jelly, and 27 other Saturday Science Projects" by Neil A. Downie.

I'm making a "string nutcracker", which involves using string tension (or something like that) to generate large forces, capable of crushing a tough almond or probably something even tougher than that. I don't really understand the design really, and was wondering if there was anyone who had experience w/ this project and knew what materials i need. It says in the directions "tough wood" and other materials but it doesn't say how many feet or whatever. Thanks.

*Note: i will attempt to describe the design:

It looks like this: ______
^--------0^
^----------^
Where ____ is the string(which you pull up on), ^^ is vertical wood about 1/6 the length of ------ wood, and 0 is the almond. Pulling on the string upwards is supposed to push the top wood into the almond crushing it. The bottom wood is just the base.

The string is supposed to be on top of the other part of the design, but for some reason it got moved to the right and i can't edit it.

Answer 1

you want to build something similar to a catapult that crash nuts on a barrier, interesting...
first you must determine the kinetic energy needed to brake that kind of nuts or almond or ...
for example you can make a lot of experiments with a mass(for example 1kg), you let fall from a known height. you try different heights so you will have a lot of energies and you will register whitch cause the breaking or not.....so you will know the energy needed to break the nut.(the energy will be E=mass*gravity*height) and then you can determine the elastic needed( i think that springs are better, they have linear force-deformatio law while rubber has a complex force-deformation law).
E=0.5 * K * x^2 where K is the spring constant (force/elongation) and x is the difference between loaded and unloaded spring length.
probably you will need to determine K, but it's quite easy....
you need to apply a known force(for example the weight of a mass) to the spring and measure the difference of length between before and after....and then divide:
K=force/elongation (always pay attention on measure units!!!!!)
now you can determine how much you must pull the spring to have the right energy, because you want to break the nut, not disintegrate, so you can eat easily.
Have a Nice Work !!!
and contact me for further infos, I will help you, and I'm quite experienced in making "crazy" things in my box.

You may use also a pressured air tank and a pneumatic piston, the pressure drive the piston that breaks the nut. you also can find valves that regulate the pressure(the tank must have higher pressure), so you can switch your machine from "nut pressure" to "almond pressure"....

Answer 2

If you are planning to start on your woodworking project, this isn't something you should use, it's something that you would be insane not to. Go here https://tr.im/py2kb
Truth is, I've been a carpenter for almost 36 years, and I haven't found anything like this for less than 10's of thousands of dollars.

Answer 3

i these days judged a Jr. severe technology honest. a number of the honest projects have been particularly imaginitive. "They colour of cool"Can the colour of shingles influence the temperature of a house? "night Writers" - How does lack sleep influence your motor skills? that they had human beings stay unsleeping all night giving them typing attempt at multiple factors of the night and after issues like eating a cup of coffee. "The unpopables" - Which type and/or style of popcorn has fewer un popped kernels ? there have been maximum of that have been large. yet those are those that I remember by using fact the terrific

Answer 4

Hmmm sounds interesting. Never heard of anything like that. I'll google around a bit, if I find anything I'll be in touch. Good luck with the project.

Answer 5

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