Vibrations and Waves

Well, Physics solved the mystery of the oscillating pendulum. The data clearly showed, as theory predicts, that length of the cord is the factor that affects pendulum period (provided location does not change). Mass and amplitude have little to no effect. Also, plotting T² versus cord length gave very good values for acceleration due to gravity. Values varied from 9.77 m/s² to 10.3 m/s². Since the accepted value is 9.81 m/s², a good job was done by all.

Honors Physics will conduct the pendulum experiment tomorrow and this will build on the wave introduction that we began in class today. It will be interesting to see how the data compares with the data collected yesterday. Read over the lab protocol tonight and be ready to get rolling when we get to class. Hopefully, we can get the data collected and analyzed during a single lab period. For those who like to think ahead, you will also conduct Extension #1 for the investigation - you might be puzzling out how you might perform that calculation with the data you will be collecting (Hint: the equations for pendulum period listed above the Extension will be a big help).

Physical Science found out that standing waves are not easy to form and maintain. The frequency has to be just such that a multiple of 0.5x wavelength will form perfectly in the medium. You were only able to get 0.5x, 1x and 1.5x wavelength to form on the rope. No other fraction/multiple would produce a standing wave. The inverse relationship between frequency and wavelength was evident and most groups were able to discern that using different ropes produced waves that traveled at different speeds. Since wave speed is dependent on the nature of the medium, this was the expected result. Complete your wave worksheets tonight so that we can go over them as part of the exam review tomorrow. Exam on Thursday and for Friday, your next lab block, you will conduct an experiment to determine the speed of sound in air.