The impedance of a material is Z=rhoc, the density times the speed of sound. Consider the following information: Zlung=0.18×106kg s/m2. Zfat=1.34×106kg s/m2. What fraction of the incident intensity of a sound pulse will be reflected when sound travels from fat into lung? Express your answer in percent.

Consider a file currently consisting of 200 blocks. assume that the file control block (and the index block in the case of indexed allocation) is already in memory. calculate how many disk i/o operations are required for contiguous, linked, and indexed (single-level) allocation strategies, for each of the conditions listed below. in the contiguous-allocation case, assume that there is not room to grow at the beginning but there is room to grow at the end. also assume that the block information to be added is stored in memory.