These ideas come from Jeff DeCurtins at Menlo Atherton High School in Atherton, CA. You can contact him at: jdecurti@seq.orgFor momentum, I've had my students do don't break the egg. I have them design and build a capsule that goes on top of a water rocket that they also build from empty 2-liter soda bottles. I've made a rocket launcher out of PVC and a bicycle pump. Rockets go as high as 200 ft. Eggs rarely survive but EVERYBODY loves being out on the field shooting these things off.
Click here for Word document describing the launcher and the project more fully.
Click here for pdf document describing the launcher and the project more fully.Last year I started having my students do in-class research/engineering projects of their own choice (or of my choice if their group wasn't creative). These included the following:
* claymation: they produced stop-action movies by a sequence of shots with a digital camera. They had to move the clay (or other props) in such a way that measurable constant velocity or acceleration was visible in the resulting clip.* air friction vs. cross-sectional area: they designed and did an experiment that used our sonic ranger probe to measure and plot the terminal velocity of various sized (but constant massed) objects falling. Easiest is to use coffee filters as flat sheets such as cardboard don't fall straight down.
*motion of bubbles rising in a column of water: do bubbles accelerate as they rise? do smaller bubbles rise slower or faster than bigger bubbles? A student brought in a long plastic tube and videotaped bubbles rising then analyzed the video for bubble motion.
* what is the terminal velocity of a raindrop? a student borrowed a titration setup from chemistry and measured the velocities of fixed-size drops falling from different heights.
* precision of our directional hearing: a group investigated how well we can point toward the source of a sound when our eyes are closed.
* speed of nerve impulses: a group investigated how fast nerve impulses travel by using two force sensors, one to cause and record the time of a sensation (say on your toe) and the other to record the time of your response to it (by tapping your finger on the probe). They had to create a math model incorporating reaction time as well as impulse travel time and fit the model over various distances.
* what is the tensile strength of hair? How does it compare to other thin things?
* why are the centers of ice cubes cloudy?
* why does water stream coming out of a faucet get narrower as it falls and can we predict the radius of the stream as a function of distance fallen AND if we actually measure it, how well does our prediction match the data?
* what is the energy per unit area delivered by sunlight? Students made a small, insulated sunlight-absorber with water and measured temperature rise over time (using a large telescope to increase the amount of sunlight channeled into the water).
Updated 5/10/08