Ideas for Scientific Investigations

    These are merely some suggestions - you are free to select other topics. It's a good idea to talk over your project with me prior to doing too much work on it. Be alert to safety hazards.

    Physics IDEAS
    Chemistry IDEAS
     

Physics Ideas:
How accurate are numerical integration simulations such as Interactive Physics II? Take some situations which you can solve analytically, and also simulate them using Interactive Physics II. Compare the accuracy of the results (you may wish to try this with several different accuracy settings in Interactive Physics II.) This is available only on MacIntosh format.

A favorite lecture demonstration is the following. Drop two balls of rather different masses (e.g. a tennis ball and a soccer ball) with the large ball on the bottom. After collision with the floor the small ball is shot up with a rather impressive speed! Perform this experiment, and then analyze it theoretically. Compare predictions and observations for the mass ratio of your two objects.

The coefficient of restitution is defined as the relative velocity just after a collision to the relative velocity just before. If one of the objects is very large, this would correspond to the velocity before impact to the velocity after. For example, a very bouncy ball has a coefficient of restitution very near 1, while a very "dead" object will have a value which is nearer to 0. The surprising thing is that the coefficient of restitution depends mainly only on the materials, and not on the actual speeds. You can test this by measuring accurately the time between bounces using the Motion Sensor software to record the bounces in the Pasco software, and then calculate the velocities. With a ping pong ball on a solid surface, you can probably measure 15 or so bounces.

Consumer survey: compare at least two different brands of tennis balls by measuring the coefficient of restitution of each. It might be interesting to do this with new balls at several different temperatures, and then work them in and compare results for worn balls. Alternative: do the same thing, but for golf balls.

Is the cart-track system with the Pasco interface really frictionless? Use the interface unit to obtain a number of runs with different angles, work out the expected acceleration, and determine if there is any friction within the accuracy of the results obtained.

Stability of rigid body rotations. Take an object such as a book held with elastic bands or a block of wood. Try to throw it in the air while it is spinning about each of the three principal axes. You should find that two are stable, and one is not. Videotape may be helpful for the analysis. Alternatively, or in addition, study the spinning of a tennis racket about its three principal axes. The corresponding theorem is sometimes called the "tennis racket theorem". Reference: J.B. Marion, S.T. Thornton (1988), Classical Dynamics, pg. 401-403 (and preceding pages as background).

An egg-timer will weigh the same whether some of the sand is in free fall or not. Confirm this with observations, state when it is not true (and try to confirm that) and show the theoretical derivation. Note: you may want to construct a larger apparatus to make the weight measurements more precise. References: Reid, W.P. (1967) "Weight of an hourglass" Am. J. Phys., 35, 351; Walker, J. (1977) The Flying Circus of Physics With Answers (John Wiley & Sons), pg. 26, 233.

What would (will?) happen when a 10 km comet or asteroid impacts the Earth? Use some simple ideas in physics to perform calculations related to this question. For example, work out the kinetic energy, and express in terms of kilotons of TNT. Consider the tsunami which would be produced by an ocean impact.

How does a falling chimney (or building break). Build up a tall chimney by stacking children's blocks or pieces of wood. Which way does it break (i.e. concave or convex or neither). References for the theory of this: Sutton, R.M. (1936), "Concerning falling chimneys", Science, 84, 246; Reynolds, J.B. (1938) "Falling chimney", Science, 87, 186; Jones, A.T. (1946) "The falling chimney", 14, 275; Walker, J. (1977) The Flying Circus of Physics With Answers (John Wiley & Sons), pg. 36.

In physics we make the statement that (neglecting friction) objects of different mass fall at the same rate. Prove this experimentally (e.g. videotape the fall of objects of different mass, or by some other method which you come up with).

Collisions on an air track. Videotape collisions between gliders of different masses, and compare to the velocity ratios expected from a theoretical analysis.

There is lots of interesting physics in the bicycle. You might want to read the following references, and then decide on some specific aspect which you could consider for a scientific investigation. References: Jones, A.T. (1942), "Physics and bicycles", Am. J. Phys., 10, 332; Wilson, S.S., (Mar., 1973), "Bicycle Technology", Sci. Amer., 228, 81.

Bode's Law (see http://www.itsnet.com/home/bmager/public_html/pluto/bodeslaw.html) is able to predict the positions of the planets (except for Pluto, which is generally believed to have been produced elsewhere in the solar system) with remarkable accuracy. It is still not clear whether this is simply chance, or if there is more to it than that. You might want to consider how many possible numerical sequences which we would find remarkable, and estimate whether it is not surprising that one of these match the actual locations of the planets.

Another statement which we make in physics is that in the absence of friction a dropped bullet and one fired horizontally from a gun would both fall through the same vertical distance in the same time. Establish an experimental way to verify this. One possibility might be to roll objects off a vertical table. Use two Pasco motion sensors to record the time of the rolling object and the time when the object hits the floor (using the SoundEdit software). By rolling the object at different speeds one obtains different horizontal components of the initial velocity.

Obtain a plot of v vs t for an object as it approaches terminal velocity, and compare to the analytic results. One approach  is to drop weights with balloons attached, and use the Pasco motion sensotr to measure distance vs. time, and then v vs. t.

How large would an asteroid (assume spherical with a density of 3400 kg/m^3) have to be so that you could not jump off it? You will first want to determine the maximum speed which you can jump from earth. Do some jumps and measure the height (using video or straight measurement by a human observer). From this maximum height you can figure out what the initial velocity must have been. 
Physics of karate Calculate the minimum velocity which would be necessary in order to break a pine board. Now videotape an actual breaking, and estimate the velocity. Caution: Get advice prior to trying this, use a dry pine board, no large knots, break with the grain and wear gloves to protect yourself from splinters.

What would be the theoretical minimum time to run the 100 m dash? This will depend on the maximum acceleration, which in turn depends on the maximum coefficient of static friction between a running shoe and a track. Devise a way to measure the coefficient of friction, compute the maximum acceleration, and the time if this acceleration could be continued throughout the race. Discuss which assumptions are not reasonable.

Write a computer program (or spreadsheet) to show how the flight of a golf ball and horizontal range will depend upon the initial velocity and angle with which it leaves the ground. What would be the effect of an elevated tee? Provide some interesting tables which would be helpful to a golfer.

Physics of billiards. There are lots of interesting physics in billiards. Take some subset and combine theoretical and observational studies.

Safe driving speeds under different conditions. Get a tire and devise a way to measure its static and kinetic coefficients of friction under different road conditions (e.g. pavement, wet pavement, icy pavement, etc.). Now use these results to establish a table of stopping times and distances for various initial speeds.

Look up in a reference source the amount of time that it takes the solar system to go once around the center of our galaxy. Use this to calculate a mass. Will this be the mass of the entire galaxy, the mass of what is inside the sun's position, or something else? Look up information on "dark matter" and explain the evidence for dark matter in galaxies.

 Chemistry Ideas:

Experiment with different shampoos/conditioners. How do they affect different hair? What ingredients cause this effect?

What is a water softener? How does it work? Why is water hard or soft?

What happens to your hair when you bleach it? color it? perm it? straighten it? Do some testing on real hair using a variety of these products. How does the hair change? Chemically speaking, what is happening?

How can energy be generated? What is the cost of each type? How could generators be improved to make them more efficient?

Look in your Chem Com book in the Extending the Concepts sections.

How do real water treatment plants purify water? Which methods are most efficient? Most productive? Least expensive? Create your own water purifier and test the end product for purity

How can you prevent rusting of meterials? Research ways to create a coating to prevent the rusting of a metal left outside or in humidity.

What is the effect of various food additives to different materials...hair, nails, teeth. You can't use human subjects but you can use the parts that come off of them.

How do nail strentheners work? What chemical is in them? IS there a common chemical you could use at home that would have the same effect?

 
Using salt, soap, and isopropyl alochol remove the DNA from various fruits. Which work best? Do some research to figure out which type of fruit might have the most DNA

 

Have you ever wondered what happens inside of an egg when it is hard
boiled?  Would larger eggs take longer to cook?  How hot does the water
have to be?  Will higher water temperatures make the eggs cook faster?
				
					 
				
			
Why does salt melt ice?  Do you think that mixtures of different salts
such as calcium chloride and sodium chloride would work better?  Would
sugar melt ice, or chalk?
				
					 
				
			
Some ant-acid tablets like Tums claim they work better than other
products and that they contain calcium.  How could both of these claims
be tested?  Do some tablets contain magnesium or aluminum?
				
					 
				
			
Some people dye their hair.  How long does it take for the dyeing to be
completed?  How long will the dye last?  Which brands are better?  What
chemical reactions occur during the bleaching or hair using peroxides? 
Will different types of hair react differently?
				
					 
				
			
You may use a hair spray.  What chemicals are present in sprays?  Do
that resemble glues?  Will that dissolve in water?
				
					 
				
			
How do products like Bounce act to soften clothes after they are washed
and dried?  What happens when clothes are ironed to stiffen them and
take out wrinkles?
				
					 
				
			
Some shampoos contain both a conditioner and shampoo.  Some are single
products. What chemicals do each contain?  Why do they work?  Can you
mix  a conditioner and a shampoo in the same bottle and get the same
results as with the combination product?
				
					 
				
			
Some paper is slick and shiny while other paper is rough.  Is all paper 
the same chemically?  if you use a pen on different types  of paper will
the ink stick as well or will it stain?
				
					 
				
			
Do you use anti-perspirants?  How do they work chemically?  Do they
absorb water or tighten the skin?  Can some chemicals help to keep
things dry?  Have you ever found a little  package inside of potato
chips, or in electronic equipment packages to keep water out?
				
					 
				
			
You're heard a lot about acid rain.  Do you think there is acid snow or
ice as well?
				
					 
				
			
Breakfast cereals contain iron.  Could you detect iron metal powder if
it was present in the cereal?  Do you think powdered iron is really good
for you?
				
					 
				
			
Tungsten metal is used as the filaments in some light bulbs. How could
you test this?  Why is tungsten used and not iron or magnesium
(Magnesium is actually used in a special type of bulbs.  Do you know
which?)?
				
					 
				
			
The ink used in washable markers is different from the ink used in
permanent marking pens.  How do they differ chemically?  Is washable ink
really easy to remove?  Does it get harder to clean after a certain
amount of time?
				
					 

This page maintained by Debra Dimas, Santa Teresa High School. Last updated August 15, 2006.