Science Buddies: "Ask an Expert"

Our 1st grade son is doing a experiment on whether a plastic or foil taco sauce packet will squirt the farthest when burst.
We are first timers and are having challenges researching this. We have found that plastic will burst at higher pressure and will bulge prior to bursting. This is all our own findings. Could you please help us find more resources to research as we are
not certain how to prove the results?
Please note that the packets are standard condiment packets from a fast food restaurant.

Thanks,

I wasn't able to identify any research sources specific to your experiment. But I can tell you a few general materials engineering principles to keep in mind.

The "pressure" required to burst different packages will depend on two key variables: 1) the material of the packet and 2) the mechanical strength of the bond that closes the packet.

If you devise a method to control the amount of force applied to each packet, you should be able to get good, useful scientific results. I'd suggest some device where you can apply weight to the packets. You could record the weight at which a packet bursts and compare results.

To understand the strength of the material used, you would have to construct a more sophisticated device. You would cut open a number of packets, clean them, and then measure the force require to tear them when you tried to pull them apart. The size of each material sample would have to be the same so that you could get meaningful results.

I did manage to find a couple general science projects that deal with the strength of materials similar to your experiment. Take a look at these to see if they help.

http://www.projects.juliantrubin.com/sc ... oon_1.html

http://www.selah.k12.wa.us/SOAR/SciProj ... rmenL.html

Good luck and have fun working with your student on this experiment.

Thank you for your advice it has helped a great deal. When we tested the strength of the bond, the foil bond faild at an average of 9lbs. The plastic bond proved to be stronger than the plastic its self. The plastic stretched and broke at 13lbs but the bond held strong. When we tested the weight need to burst the packets the plastaic again need more weight at 9lbs vs the 3lbs to break the foil. I need to point out that the foil broke at the bond under the weight while the plastic did not. We are just about ready to write the hypothesis but before we do could you please let me know if we understood the results correctly? We dont want to confuse our son. With foil being the weaker material more energy will transfer to its content allowing it travel farther. The Plastic packet will absorb some of the energy in the streatching of the material. I think. I am in no way a scientist.
Thank you.