Jose1
Posts: 1
Joined: Mon Dec 02, 2013 7:33 pm

### Science Fair

I need help with expanding my research project.
What is a good experiment with silly putty? I've created different types of silly putty but i need to expand. a good question would be a start. Help….

tdaly
Former Expert
Posts: 1415
Joined: Sat Nov 08, 2003 11:27 pm
Occupation: Planetary Scientist

### Re: Science Fair

Hi Jose1,

One of the neat things about silly putty is that its rheological properties change depending on how fast you deform it. In other words, the behavior of silly putty is "strain-rate dependent". For example, if you pull slowly on silly putty, it will act a bit like melted cheese on a pizza--stretch out and form stringers. But, if you pull on silly putty very quickly, it will break instead of flow. The viscosity of silly putty, which is defined as how much stress you apply to the putty divided by how much it deforms per unit time, depends on temperature.

This is a pretty basic, but clear, discussion of silly putty rheology: http://www-old.me.gatech.edu/jonathan.c ... yputty.pdf

This website provides a more advanced discussion of silly putty's rheology (silicone putty = silly putty): http://www.geology.um.maine.edu/geodyna ... heory.html

For an overview of what strain rate is, take a look at this Wikipedia article: http://en.wikipedia.org/wiki/Strain_rate

So, you could look at a couple of different variables. One is strain rate, the other is temperature. Read up on the rheology of silly putty (the links above are a good starting point, but I suggest doing some additional research on your own), and see if you can think of a question you could test about how strain rate or temperature affects the behavior of silly putty. This Science Buddies webpage does an excellent job of explaining how to formulate a good question:

http://www.sciencebuddies.org/science-f ... tion.shtml

If you get stuck, feel free to post back. I'll get an email when you reply to this post, so I'll get back to you within a day of when you reply.
All the best,
Terik

quaid_forbes
Posts: 4
Joined: Fri May 09, 2014 10:25 pm
Occupation: student year 8

why its amusing?