Need Ideas

[Amber]

I need ideas for a physics project. The teacher said that we could do anything, so long as we can get hold of the equipment for it. I basically need to answer a question or have some kind of title which I could investigate, for example, drag forces on different shape objects, variation of surface tension with temperature. But I want to do something interesting so that I don't get bored of it half way. It's a project that will take about 3 months to complete, inclulding the experiments and write-up.

Thanks,
Amber.

[Tormod]

What grade, Amber?

[Amber]

I'm not sure what the equivalent is, but I'm in year 13 in England.

[Pyrotex]

Originally Posted by Amber

I'm not sure what the equivalent is, but I'm in year 13 in England.

There is a physics experiment I have always wanted to do but never got around to. To do it you may need a good camera or even a video camera capable of taking slow-motion shots. You will probably need an extra lens so that you can record images that are only an inch or two across, with magnification.

Give a name to and explain the cause of the following phenomenon:
Get a bottle of thick, translucent hair shampoo. Ordinary stuff. In the USA, we have PRELL, the cheapest around, the "green stuff". Shampoo.

Put a shallow white bowl on the table and mount the bottle above so you have fine control of how fast the shampoo streams out. Get the minimum stream you can without it breaking up into droplets. Let the stream impact upon the gathering pool of shampoo below. Look carefully at the point of impact.

You will see the stream hit and form a mound. Then you will see large (0.5 to 2.0 inch) LOOPS of shampoo suddenly shoot out to the side. It happens very quickly. And I typically see about 20 loops a minute. Try varying the rate of flow of shampoo to see if this affects the number and/or size of the loops.

How are the loops formed? Why are they shot out to the side? What the heck is going on here?

[InfiniteNow]

Don't know if you have this available to you, Amber, but back in 8th grade a good friend of mine gave me this book:

Amazon.com: Great Experiments in Physics:...
Amazon.com: Great Experiments in Physics:...

It's pretty cool, and would certainly get your creative juices flowing.


Best of luck with the project!


edit: The book is "Great Experiments in Physics," and it is, by no means, meant to be read at an 8th grade level. Cheers.

[InfiniteNow]

Originally Posted by Pyrotex

You will see the stream hit and form a mound. Then you will see large (0.5 to 2.0 inch) LOOPS of shampoo suddenly shoot out to the side. It happens very quickly. And I typically see about 20 loops a minute. Try varying the rate of flow of shampoo to see if this affects the number and/or size of the loops.

How are the loops formed? Why are they shot out to the side? What the heck is going on here?

Sounds to me a bit like Brownian motion...but, I'm no physicist.

[CraigD]

Originally Posted by Pyrotex

Put a shallow white bowl on the table and mount the bottle above so you have fine control of how fast the shampoo streams out. Get the minimum stream you can without it breaking up into droplets. Let the stream impact upon the gathering pool of shampoo below. Look carefully at the point of impact.

You will see the stream hit and form a mound. Then you will see large (0.5 to 2.0 inch) LOOPS of shampoo suddenly shoot out to the side. It happens very quickly. And I typically see about 20 loops a minute. Try varying the rate of flow of shampoo to see if this affects the number and/or size of the loops.

How are the loops formed? Why are they shot out to the side? What the heck is going on here?

It’s a phenomenon associated with non-Newtonian liquids. What is happening is that the viscosity of the shampoo increases when it's compressed on impact, causing it to form a column that then coils, loops, etc. Once the compression is released, it turns back into ordinary liquid, and flows away.

Thicker liquids, such as pancake syrup, do it slower, and are easier to observe.

There’s a fun stunt along these lines, popular with phys-sci teachers: fill a large tub with a mixture of water and corn starch. You can gently splash the solution out of the tub. Take a paddle and slap it hard and fast. It doesn’t splatter at all. Have faith in Science. Be sure to use enough corn starch.

[Jay-qu]

Rockets are always good!

[Amber]

Thank you for all your ideas. However, I'm not sure I understand all the concepts. Do you have any easier to understand ideas? Basically, I need to get a good set of results that I can analyse and draw up a conclusion.

Thanks,
Amber

[InfiniteNow]

Originally Posted by Amber

Thank you for all your ideas. However, I'm not sure I understand all the concepts. Do you have any easier to understand ideas? Basically, I need to get a good set of results that I can analyse and draw up a conclusion.

Thanks,
Amber

In my high school physics class, we had to build an item using nothing but popsicle sticks and glue that would protect an unboiled egg being dropped from a high spot (like the roof of a building or at the top of the bleachers at our stadium) from breaking.

We'd design it, build it, talk about our design, and why/how it distrubuted the impact enough to protect the egg without using something soft like a pillow.

How about something like that?

Even if the egg breaks, you can speak of why... It's a win/win.