A) SONAR which stands for Sound Navigation and Ranging is used to navigate and find out the location of objects .It works on the Principle of Echo-location.An ultrasonic sound wave is sent and the time taken by it to return is noted.and the distace of the object is found out ny the formula .: v=2d/t

 3 X 10^{8} =2d/2X 10^{-5} 

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