For this project, you'll use a baseball as a pendulum weight, studying the motion of the ball with and without spin. Wrap a rubber band around the ball, and tie a string to the rubber band. Fasten the string so that the ball hangs down and can swing freely. Mark a regular grid on cardboard, and place it directly beneath the ball to measure the motion. You can also time the oscillations with a stopwatch. Lift the ball along one of the grid axes, and let it go. Observe the motion and record…
What do knots, maps, mazes, driving directions, and doughnuts have in common? The answer is topology, a branch of mathematics that studies the spatial properties and connections of an object. Topology has sometimes been called rubber-sheet geometry because it does not distinguish between a circle and a square (a circle made out of a rubber band can be stretched into a square) but does distinguish between a circle and a figure eight (you cannot stretch a figure eight into a circle without…
If you have a multi-speed bike, you know that you can make it easier or harder to pedal just by shifting gears. Ever wonder how that works? You can investigate this a number of ways. A basic approach is to use a selection of spools of thread (with different diameters), a board with two nails, and a rubber band. Place a spool over each nail, and put the rubber band over them. Mark the 12:00 position on each spool so that you can count revolutions. Turn one spool through a full circle and…
Many materials expand when heated and contract when cooled. What do you think will happen to the elasticity (stretchiness) of a rubber band when it is heated or cooled to various temperatures?
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Average (6-10 days)
This project requires some specialty items. They can all be purchased online, or you may be able to borrow them from school. See the Materials list for details.
Low ($20 - $50)
Adult supervision is required for heating and pouring boiling water.
If you have ever been shot with a rubber band then you know it has energy in it, enough energy to smack you in the arm and cause a sting! But just how much energy does a rubber band have? In this experiment you will find out how the stretching of a rubber band affects the amount of energy that springs out of it.
Fill a jar a little more than half full with fresh water. Make a solution of salt water, and add a drop or two of food coloring to it. Pour the salt water solution into a plastic cup with a small hole in the bottom, and then place the cup in the jar with fresh water. (The only connection between the fresh and salt water should be via the hole in the bottom of the cup.) With the right combination of hole size and salt concentration, you will see an oscillating current develop in the jar. …
Here's a project idea for all of you bakers out there. What happens if you try your favorite muffin recipe with different types of flour (e.g., white, whole wheat, rye, soy, etc.)? Think of ways you can measure the results. How would you measure the density of a muffin? A kitchen scale would definitely be useful for this project, both for measuring the results and for portioning out the batter for equal-sized muffins. What other measures might be of interest? (Nakajima, 2005)
How much difference does the spiraling motion of a well-thrown football make on the distance of the throw (compared to wobbling, or end-over-end motion of the ball)? Think of a way to reproducibly produce the desired ball motion and launch it with a constant force to find out. (For more information on the physics, see Gay, 2004.)
Is soil structure an important factor in earthquake dynamics? Investigate soil liquefaction and how different soil types respond to earthquake movements. Are movements more dramatic in sandy/loamy or clay type soils? Which soil structures are most stable? Which are the most volatile? (MCEER, 2005)
When the punter is trying to hit the "coffin corner" (within the opposing team's 10-yard line), out of bounds, what is the best angle to kick the ball for correct distance and maximum "hang time?" (For more information on the physics involved, see: Gay, 2004, Chapters 4 and 5.)
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