Physics
A moving ship continuously sends in ultrasonic pulses down to the sed-bed and records the time delays of the reflected pulses. The variation of time delays recorded versus the positions of the ship is plotted in the following graph. Which of the position indicates the deepest sea bed?
- A
- B
- C
- D
Answer
B
Reason — The depth of the ocean floor is determined by measuring the time it takes for a signal to be received back. The greatest time delay, observed at position B, indicates the deepest sea-bed. This is because sound must travel a greater distance, resulting in a longer time delay.
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