# Q & A: science fair projects

Q:
So im in 8th grade i have a physics at home experiment project due on the 11 of December that gives me like 3 weeks. I need to do a physics experiment that I must present to the class(i don't have to do it in-front of the class i can make a video) But this is the first the first time i have ever learned about like legit physics the year before we did astronomy and cells but that's the closets iv gotten to doing anything with physics. So please i need some help thinking about an idea if i can il get the rubric tomorrow(November 22/13) THANKS GUYS.I would like to do something fun not boring like Water displacement im in 8th grade i would like to do some stuff with fire or make rockets or stuff i can get parent supervision and i got goggles so don't wory
- Heary (age 14)
South Barrignton,IL,US
A:

There are zillions of possible projects. I'll try to think of one that would have some fun ingedients and also show some real points about the world.

I bet you can get some dry ice. (Be sure to handle it with gloves and some eye protection.)

For starters, you can just put some in water and watch it bubble up, as the solid changes to a gas (CO2).

Then you can show how much more space the gas takes up by putting some in a balloon, tying off the balloon, and watching it expand. You can measure the volume of the solid before and the volume of the balloon before and after to see the ratio of the gas volume to the solid volume.

Then here's an idea that just came to mind. Put the balloon on a good scale before the dry ice turns to gas. Watch how the weight changes as the balloon expands. Then think about and explain what you just weighed when you measured that change.

Mike W.

(published on 11/21/2013)