<hello,
i am a physics and math high school teacher;
thanks for this excellent mail list !
i'd like to ask you information about possible outdoor experiments you
do or have done in the past;>
Roberto,
Here are some of my favorite activities. They may take some time but the learning value seems to be high. Unfortunately I do not have lesson plans in English, let alone Spanish as I have not taught any physics in a long time. I am also rather linguistically challenged but I could write up a rough, untested plan and attempt a translation if you need one - contact me off list.
Average versus instantaneous velocity and acceleration: Roll a basketball down a hill - slope does not have to be large. (Caution - I originally used a bowling ball - not recommended as it took an unexpected bounce and went through the windshield of the department's van.) Space students with stop watches at 2 to 5 meter intervals (depending on number of students and steepness of incline). Record data - distance versus time. Then go back to the classroom and calculate average/interval velocity and acceleration. If you don't finish all the calculations your students can complete the exercise as a homework assignment. You can challenge your best students by asking them to determine approximately the angle of the slope from the acceleration data. Or you can simply save the data and do the slope calculation later when you talk about vector components. Students seem to enjoy the calculation part a lot more because they participated in getting the data - they are physically part of the experiment. If you just give them a "prepared" data set it tends to be an exercise in tedium.
The second is the "Refraction March". Have everyone line up in a straight line in a parking lot or better - soccer field with a line to walk across. Practice taking "adult" steps and "baby" steps. If someone wants to be the "drummer" and beat a cadence all the better. Start out with everyone parallel to and about 5 meters away from the line. Instruct the students to take "adult" steps until they get to the line. Once they cross the line they take baby steps. Repeat but this time line up so the students are at an angle - say 20 degrees from the line. Point out to students how the change in speed results in a direction change when the boundary is crossed. Just like refraction.
Doppler: Mount a horn on a bicycle or carried by someone riding a skateboard or whatever. Record the sound as the bicycle goes by. Can be done using a laptop and microphone or use a tape recorder or whatever and play it back into the computer. Analyze the sounds to find the doppler shift, then calculate the speed of the bicycle. A couple of free programs that do this easily are Pratt and Audacity.
Interference: In a large open area place two loudspeakers (ones with good bass response) about two meters apart. Connect a function generator to the amplifier and set the generator at 200 to 300 hertz. You can alter the frequency to determine what frequency works best. Students walk in front of the speakers and map the points of maximum and minimum loudness. The map should turn into a plot of the interference pattern. Now reverse the leads on one of the loudspeakers and repeat. See if your students can figure out which wiring leads to constuctive versus destructive interference along a line between the two speakers.
Change the frequency and make another plot. How does the interference pattern change?
As the other list members have pointed out there are many other activities.