Ideas on science project

[Schmoe]

I was talking to my 14 year old daughter and was discussing different oils and how they prevent friction. She said that would be a cool idea for a science project to show how different oils help friction.
I was thinking of some sort of heavy weight on a steel incline at a standard slope. Use different oil weights like car oil, then some heavy grease and compare them all to say water or something. What do ya'll think?

 

[Alfred_B]

You could do viscosity changes with different oils based on temperature. Cool one batch with dry ice and have another batch at room temperature.

Easier to demonstrate than trying to calculate friction.

 

[wymi516]

This is just for fun but I instantly remembered this:
https://youtu.be/MXMGAnyYoog

 

[Al]

You should talk a bit about lubrication/friction:https://en.wikipedia.org/wiki/Lubrication

 

[ARCOgraphite]

I wouldn't. Polluting the child's mind already?
You need more sophistication for Jr Highschool.

Does she know how to calc mu and measure Normal forces? May be something to learn along the journey.

 

[Yah-Tah-Hey]

Originally Posted By: Alfred_B
You could do viscosity changes with different oils based on temperature. Cool one batch with dry ice and have another batch at room temperature.

Easier to demonstrate than trying to calculate friction.
Right. She could include the old STP commercial that supposedly showed how slippery the product was by dipping a screwdriver tip in STP and then showing a man unable to grip tool hard enough to keep it from sliding out of his fingers. I think several STP claims were challenged by the FTC. Anybody remember that commercial from the fifties?

 

[sleddriver]

May be tough to actually tell a difference in such a test. You could use a fish scale to measure with and test out your idea.

The three phases of water would be good. Rather fascinating actually. All the energy put into heating a block of ice won't begin heating the water until all of the solid ice has melted. At such point, the water will still be at 32F. Likewise with boiling water in a pot. The temp of the water will remain around 212F until all the water is evaporated regardless of how much heat you put into it. These are the phase points.

You can also take a metal gallon can put a pint or two of water inside, put it on a burner until the water boils and steam fills the can. Then screw the cap on tight, remove the can from the heat and watch what happens.

Another good experiment is figuring out why some ice cubes are cloudy and some are not. Try making a block of 100% clear ice at home. Then measure which ice lasts longer: Clear or cloudy? Why?

 

[Al]

Originally Posted By: Alfred_B
You could do viscosity changes with different oils based on temperature. Cool one batch with dry ice and have another batch at room temperature.

Easier to demonstrate than trying to calculate friction.


That will get unwieldy as the temp of the lub warms up when you apply it. A better bet is to show how viscosity works aith different loads and different weights.

Do a very light load with light and heavy oil. This could show that the viscisoty is to heavy and actually builds up friction (in the liquid). The lighter fluid will allow the load to move easier.

Do a heavy load with light and heavy oil. The opposite will occur.

The classic bearing equation is based on speed, load and viscosity. Deal with load and viscosity. Yes voscosity is a function of temperature. You could try to work that in if you want.

 

[BrocLuno]

If you are going to do the slope lubricity demo, use a clean piece of say 1/4x6" aluminum and use one side for the oil and one for the heavy gear grease. Can't run them back to back on the same side as they will interfere with each other and the results will be too similar

 

[Shannow]

Personally, I think that the experiment would be too hard...e.g. the grease you could probably stand the rig near vertical, and with the oil, there's a phenmenon where if you get the film a certain thickness, the items are "stuck" together by air pressure.

the three phases of water are a good one.

Along with super cooled water snap freezing (does this count as a forth), and superheated water snap boiling (fifth ??)

My daughter is doing hers on toothpastes, mouthwashes, the 0.00 BAC for learner drivers and provisional licence, and how long after using those products you show a positive reading.... 0.026 after cleaning teeth with quite a few toothpastes, 0.03+ after mouthwashes, even some "alcohol free".

Naturally it clears after 15 mins or so, but in a morning rush could make for an uncomfortable traffic stop.