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4-23-09 Good afternoon I am Janelle Stelson. I join you here today at the Manheim Township High School in Mr. Manning seventh period physics class. Lets go inside and see what is going down. We see here that Mr. Manning begins class with a DQ or daily question. Today’s daily question reads, A pulse in a higher density medium( like a slinky) is traveling towards a boundary with a lower density medium( like a string). Then there are three questions that follow that the students are required to answer. The first question reads, the reflected pulse in a slinky (Will or will not) be inverted because. The second question reads, the speed of the reflected pulse will be (Greater than, less than, or the same as) the speed of the incident pulse? The third and final question reads, if the speed of the wave was clocked at five meters per second with a wavelength of two meters, what is the period fo the wave? The News eight team was willing to take the challenge of the students to answer the daily questions. Bob the camera man took the chance of answering the first question on the daily question. He answered will and because they are attached. The students laughed and Mr. Manning said, "sorry Bob but that is not the correct answer for either of the blanks." Jay Fredrick explained that the first blank was will not and the second blank was the mediums are different. Which would make the statement read, the reflected pulse in a slinky will not be inverted because the mediums are different. If the medium was all slinky then the pulse would be inverted. Then a student said that they would answer the question. The student was John and he answered the question filling in the blank with the same. This would make the question read the speed of the reflected pulse will be the same of the incident pulse. For the last question I offered to answer it. To figure out the anser I used the V= f times the wave length. So then I had 5=f * 2 and then I divided both sides of the equal sign by two to get the period of the wave and got 2.5. But this is the frequency so I used the equation T=1/f. I did T=1/2.5 and got .4 seconds. So I answered the third question as the period would be point four seconds. To the surprise of the students as well as myself I had gotten the last daily question right. After the daily question Mr. Manning asked the students to get out their page twelve and thirteen from their physics binders. Page twelve was titled chapter twenty sound wave superposition. The paragraph at the top read, A pair of pulses travel toward each other at equal speeds. The composite waveforms, as they pass through each other and interfere, are shown at one second intervals. In the left column note how the pulses interfere to produce the composite waveform (solid line). Make a similar construction for the two wave pulses in the right column. Like the pulses in the first column, they each travel at one space per second. The illustration of how this is done is labeled as page twelve at the top. Well we have learned quite a bit here in Mr. Manning’s physics class that if there are two different mediums then the reflected pulse will not be inverted and that the speed of the reflected pulse is the same also we learned how to find the period of a wave. This is our conclusion to the five o’clock news see you at ten back to you Brian. Amanda Rivera period 7