1. A submarine (sub A) travels through water at a speedof 8.00 m/s, emitting a sonar wave at a frequency of 1,400 Hz. Thespeed of sound in the water is 1,533 m/s. A second submarine (subB) is locate such that both submarines are traveling directlytowards each other. The second submarine is moving at 9.00 m/s a)What frequency is detected by an observer riding on sub B as thesubmarines approach each other?
b) The submarines barely miss each other and pass. Whatfrequency is detected by an observer riding on Sub B as thesubmarines recede from each other?
c) While the submarines are approaching each other someof the sound from sub A reflects from sub B and returns to sub A.If this sound were to be detected by an observer in sub A, what isits frequency?
2. By how much does the length of Dublin’s spireincrease if its temperature increases from 0 to 20C? Assume thespire is 121 m long at 0 C and is made from stainless steel(α=12x10^-6 C-1) .
