Question 8 0.77 pts The following diagram shows three plots, A, B, and C, with each plot giving information about a single sound wave moving to the right. Each plot contains two curves, one solid and one dashed, both of which are a snapshot in time of a segment of the whole wave profile as it travels through the air -- it's the displacement of all points along the wave as a function of x-position along the wave. The only difference between the solid and dashed plots is that the solid plot represents the wave profile at a different moment in time. For all of the waves A, B, and C, the interval of time separating the solid and dashed plots is the same. Rank the waves A, B, and C in increasing order of frequency (smallest on the left and largest on the right). OABC OACB OB.CA @B.AC OGAB O GB.A Question 9 0.77 pts Suppose that two different pure tones (i.e. two sounds, each of which consists of a single frequency) are played simultaneously, and the resulting sound can be represented by the following waveform which is a graph of displacement (D) versus time (t) 0.75s 0.1316's One of the sounds has a lower frequency than the other. What is that lower frequency in Hz? 133 Question 10 0.77 pts Engineers are designing a new dairy processing plant. During a certain stage of the processing, milk is flowing through a thin, horizontal pipe of a certain diameter, and after running some tests, the engineers realize that they need to increase the speed (distance traveled per unit time) of the milk as it flows along the pipe. The length of the pipe must remain the same, but they are able to change the pressure gradient along the pipe by at most 10%, and they are able to simultaneously change the pipe's diameter by at most 15%. By at most what percent can they increase the speed of milk in the pipe? Since the pipe is thin, viscosity of the milk cannot be neglected. 45.6 Question 11 0.77 pts Georgia is standing on the sidewalk waiting to cross the street on a day when the pressure and temperature in the air are sufficiently atypical that we must treat the speed of sound in air as an unknown. Two cars are driving by; a red Porsche and a Honda Accord. Perhaps not surprisingly, the Porsche is driving quite a bit faster than the Honda. When the Porsche is d Honda s driving away from Georgia, the frequency of the sound it makes is 0.9% lower than when it's dri ng toward Georgia, the frequency of the sound it makes is 1.5% higher than when the Porsche is driving away from her. When the ing toward her. Show that if v is the speed of any car is at drives past Georgia, if v is the speed of sound in air, and if fr and f.4 are the frequencies she hears when the car is driving toward her and away from her respectively, then ve = v. g i Use the equation you just derived to answer the following question: what percent higher is the speed of the Porsche compared to the speed of the Honda? 3